The self-healing solid polymer electrolytes(SHSPEs)can spontaneously eliminate mechanical damages or micro-cracks generated during the assembly or operation of lithium-ion batteries(LIBs),significantly improving cycli...The self-healing solid polymer electrolytes(SHSPEs)can spontaneously eliminate mechanical damages or micro-cracks generated during the assembly or operation of lithium-ion batteries(LIBs),significantly improving cycling performance and extending service life of LIBs.Here,we report a novel cross-linked network SHSPE(PDDP)containing hydrogen bonds and dynamic disulfide bonds with excellent self-healing properties and nonflammability.The combination of hydrogen bonding between urea groups and the metathesis reaction of dynamic disulfide bonds endows PDDP with rapid self-healing capacity at 28°C without external stimulation.Furthermore,the addition of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(EMIMTFSI)improves the ionic conductivity(1.13×10^(−4)S cm^(−1)at 28°C)and non-flammability of PDDP.The assembled Li/PDDP/LiFePO_(4)cell exhibits excellent cycling performance with a discharge capacity of 137 mA h g^(−1)after 300 cycles at 0.2 C.More importantly,the self-healed PDDP can recover almost the same ionic conductivity and cycling performance as the original PDDP.展开更多
Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant ...Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.展开更多
Elastomers with outstanding strength,toughness and healing efficiency are highly promising for many emerging fields.However,it is still a challenge to integrate all these beneficial features in one elastomer.Herein,an...Elastomers with outstanding strength,toughness and healing efficiency are highly promising for many emerging fields.However,it is still a challenge to integrate all these beneficial features in one elastomer.Herein,an asymmetric alicyclic structure adjacent to aromatic disulfide was tactfully introduced into the backbone of polyurethane(PU)elastomer.Specifically,such elastomer(PU-HPS)was fabricated by polycondensing polytetramethylene ether glycol(PTMEG),isophorone diisocyanate(IPDI)and p-hydroxydiphenyl disulfide(HPS)via one-pot method.The molecular mobility and phase morphology of PU-HPS can be tuned by adjusting the HPS content.Consequently,the dynamic exchange of hydrogen and disulfide bonds in the hard segment domains can also be tailored.The optimized sample manifests outstanding tensile strength(46.4 MPa),high toughness(109.1 MJ/m^(3)),high self-healing efficiency after fracture(90.3%),complete scratch recovery(100%)and good puncture resistance.Therefore,this work provides a facile strategy for developing robust self-healing polymers.展开更多
Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin ...Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin organic polymer with p-πconjugated structure(TPP)was rationally designed and prepared,and showed a high yield of CO(15.2 mmol g^(-1))and conversion of SAS coupled products(100%),far exceeding the organic polymer with P=O structure.The enhanced photoredox activity of TPP is ascribed to the orbital interaction between the p-orbital on phosphorus and theπ-orbitals of aromatic,which can accelerate the photoinduced charge carrier separation and improve the CO_(2)adsorption capacity.TPP can also be used for the dehydrocoupling of various benzyl mercaptans to the corresponding SAS bond products.This work provides a new concept for the efficient synthesis of disulfide bonds combined with CO_(2)reduction in a photoreaction system.展开更多
The disulfide bond plays a crucial role in the design of anti-tumor prodrugs due to its exceptional tumor-specific redox responsiveness. However, premature breaking of disulfide bonds is triggered by small amounts of ...The disulfide bond plays a crucial role in the design of anti-tumor prodrugs due to its exceptional tumor-specific redox responsiveness. However, premature breaking of disulfide bonds is triggered by small amounts of reducing substances (e.g., ascorbic acid, glutathione, uric acid and tea polyphenols) in the systemic circulation. This may lead to toxicity, particularly in oral prodrugs that require more frequent and high-dose treatments. Fine-tuning the activation kinetics of these prodrugs is a promising prospect for more efficient on-target cancer therapies. In this study, disulfide, steric disulfide, and ester bonds were used to bridge cabazitaxel (CTX) to an intestinal lymph vessel-directed triglyceride (TG) module. Then, synthetic prodrugs were efficiently incorporated into self-nanoemulsifying drug delivery system (corn oil and Maisine CC were used as the oil phase and Cremophor EL as the surfactant). All three prodrugs had excellent gastric stability and intestinal permeability. The oral bioavailability of the disulfide bond-based prodrugs (CTX-(C)S-(C)S-TG and CTX-S-S-TG) was 11.5- and 19.1-fold higher than that of the CTX solution, respectively, demonstrating good oral delivery efficiency. However, the excessive reduction sensitivity of the disulfide bond resulted in lower plasma stability and safety of CTX-S-S-TG than that of CTX-(C)S-(C)S-TG. Moreover, introducing steric hindrance into disulfide bonds could also modulate drug release and cytotoxicity, significantly improving the anti-tumor activity even compared to that of intravenous CTX solution at half dosage while minimizing off-target adverse effects. Our findings provide insights into the design and fine-tuning of different disulfide bond-based linkers, which may help identify oral prodrugs with more potent therapeutic efficacy and safety for cancer therapy.展开更多
One of the major barriers in utilizing prodrug nanocarriers for cancer therapy is the slow release of parent drug in tumors.Tumor cells generally display the higher oxidative level than normal cells,and also displayed...One of the major barriers in utilizing prodrug nanocarriers for cancer therapy is the slow release of parent drug in tumors.Tumor cells generally display the higher oxidative level than normal cells,and also displayed the heterogeneity in terms of redox homeostasis level.We previously found that the disulfide bond-linkage demonstrates surprising oxidationsensitivity to form the hydrophilic sulfoxide and sulphone groups.Herein,we develop oxidation-strengthened prodrug nanosystem loaded with pyropheophorbide a(PPa)to achieve light-activatable cascade drug release and enhance therapeutic efficacy.The disulfide bond-driven prodrug nanosystems not only respond to the redox-heterogeneity in tumor,but also respond to the exogenous oxidant(singlet oxygen)elicited by photosensitizers.Once the prodrug nanoparticles(NPs)are activated under irradiation,they would undergo an oxidative self-strengthened process,resulting in a facilitated drug cascade release.The IC50 value of the PPa@PTX-S-S NPs without irradiation was 2-fold higher than those of NPs plus irradiation.In vivo,the PPa@PTX prodrug NPs display prolonged systemic circulation and increased accumulation in tumor site.The PPa@PTXS-S NPs showed much higher efficiency than free PTX or the PPa@PTX-C-C NPs to suppress the growth of 4 T1 tumors.Therefore,this novel oxidation-strengthened disulfide-bridged prodrug-nanosystem has a great potential in the enhanced efficacy of cancer synergetic photochemotherapy.展开更多
Disulfide bond-bridging strategy has been extensively utilized to construct tumor specificity-responsive aliphatic prodrug nanoparticles(PNPs) for precise cancer therapy. Yet, there is no research shedding light on th...Disulfide bond-bridging strategy has been extensively utilized to construct tumor specificity-responsive aliphatic prodrug nanoparticles(PNPs) for precise cancer therapy. Yet, there is no research shedding light on the impacts of the saturation and cis-trans configuration of aliphatic tails on the self-assembly capacity of disulfide bond-linked prodrugs and the in vivo delivery fate of PNPs. Herein, five disulfide bond-linked docetaxelfatty acid prodrugs are designed and synthesized by using stearic acid, elaidic acid, oleic acid, linoleic acid and linolenic acid as the aliphatic tails, respectively. Interestingly, the cistrans configuration of aliphatic tails significantly influences the self-assembly features of prodrugs, and elaidic acid-linked prodrug with a trans double bond show poor self-assembly capacity. Although the aliphatic tails have almost no effect on the redox-sensitive drug release and cytotoxicity, different aliphatic tails significantly influence the chemical stability of prodrugs and the colloidal stability of PNPs, thus affecting the in vivo pharmacokinetics, biodistribution and antitumor efficacy of PNPs. Our findings illustrate how aliphatic tails affect the assembly characteristic of disulfide bond-linked aliphatic prodrugs and the in vivo delivery fate of PNPs, and thus provide theoretical basis for future development of disulfide bond-bridged aliphatic prodrugs.展开更多
Enhancing the stability of biomolecules is one of the hot topics in industry.In this study,we enhanced the stability of an important protein called LEPTIN.LEPTIN is a hormone secreted by fat cells playing an essential...Enhancing the stability of biomolecules is one of the hot topics in industry.In this study,we enhanced the stability of an important protein called LEPTIN.LEPTIN is a hormone secreted by fat cells playing an essential role in body weight and composition,and its deficiency can result in several disorders.The treatment of related LEPTIN dysfunctions is often available in the form of injection.To decrease the cost and the frequency of its applications can be achieved by increasing its lifetime through engineering LEPTIN.In this study,to engineer LEPTIN,we have introduced disulfide bonds.Disulfide By Design server was used to predict the suitable nominate pairs,which suggested three pairs of amino acids to be mutated to cysteine for disulfide bond formation.Additionally,to further evaluate the effect of combined mutations,we combined these three nominated pairs to produce three more mutants.In order to assess the effect of introduced mutations,molecular dynamic(MD)simulation was performed.The result suggests that Mutant-1 is more stable in comparison to wild-type and the other mutants.Moreover,docking results showed that the introduced mutation does not affect the receptor binding performance;therefore,it can be considered a suitable choice for future protein engineering.展开更多
A prediction method of protein disulfide bond based on support vector machine and sample selection is proposed in this paper. First, the protein sequences selected are en-coded according to a certain encoding, input d...A prediction method of protein disulfide bond based on support vector machine and sample selection is proposed in this paper. First, the protein sequences selected are en-coded according to a certain encoding, input data for the prediction model of protein disulfide bond is generated;Then sample selection technique is used to select a portion of input data as training samples of support vector machine;finally the prediction model training samples trained is used to predict protein disulfide bond. The result of simulation experiment shows that the prediction model based on support vector ma-chine and sample selection can increase the prediction accuracy of protein disulfide bond.展开更多
Kluyveromyces marxianus is a food-safe yeast with great potential for producing heterologous proteins.Improving the yield in K.marxianus remains a challenge and incorporating large-scale functional modules poses a tec...Kluyveromyces marxianus is a food-safe yeast with great potential for producing heterologous proteins.Improving the yield in K.marxianus remains a challenge and incorporating large-scale functional modules poses a technical obstacle in engineering.To address these issues,linear and circular yeast artificial chromosomes of K.marxianus(KmYACs)were constructed and loaded with disulfide bond formation modules from Pichia pastoris or K.marxianus.These modules contained up to seven genes with a maximum size of 15 kb.KmYACs carried telomeres either from K.marxianus or Tetrahymena.KmYACs were transferred successfully into K.marxianus and stably propagated without affecting the normal growth of the host,regardless of the type of telomeres and configurations of KmYACs.KmYACs increased the overall expression levels of disulfide bond formation genes and significantly enhanced the yield of various heterologous proteins.In high-density fermentation,the use of KmYACs resulted in a glucoamylase yield of 16.8 g/l,the highest reported level to date in K.marxianus.Transcriptomic and metabolomic analysis of cells containing KmYACs suggested increased flavin adenine dinucleotide biosynthesis,enhanced flux entering the tricarboxylic acid cycle,and a preferred demand for lysine and arginine as features of cells overexpressing heterologous proteins.Consistently,supplementing lysine or arginine further improved the yield.Therefore,KmYAC provides a powerful platform for manipulating large modules with enormous potential for industrial applications and fundamental research.Transferring the disulfide bond formation module via YACs proves to be an efficient strategy for improving the yield of heterologous proteins,and this strategy may be applied to optimize other microbial cell factories.展开更多
Neuregulin plays an important role in heart structure and function.Research discovered that recombinant neuregulin could reduce the degree of damage on myocardial cells caused by ischemia,hypoxia and viral infection.T...Neuregulin plays an important role in heart structure and function.Research discovered that recombinant neuregulin could reduce the degree of damage on myocardial cells caused by ischemia,hypoxia and viral infection.The primary structure,including N-terminal sequence,C-terminal sequence,PMF,accurate molecular mass,and disulfide bonding pattern of recombinant human neuregulin,have been identified by ESI-Q-TOF MS,Autoflex MALDI-TOF MS,9.4T Apex Q-FT MS and Ultraflex Ⅲ MALDI-TOF/TOF combining with two e]ymatic digestion.A abnormal peptide impurity in this drug was found and sequenced by Q-TOF MS and TOF/TOF MS,this is useful for the product quanlity control.展开更多
The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H<sub>2</sub>L (1). Characterization of t...The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H<sub>2</sub>L (1). Characterization of the ligand was performed by FT-IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O and CuCl<sub>2</sub>·2H<sub>2</sub>O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.展开更多
Solid-state fluorescent multi-color carbon dots(SFM-CDs),prepared using the same precursor(s)without the need for dispersion in a solid matrix,are highly demanded for a wide range of applications.Herein,we report a mi...Solid-state fluorescent multi-color carbon dots(SFM-CDs),prepared using the same precursor(s)without the need for dispersion in a solid matrix,are highly demanded for a wide range of applications.Herein,we report a microwave-assisted strategy for the prepara-tion of SFM-CDs with blue,yellow and red emissions within 5 min from the same precursors.The as-prepared B-CDs,Y-CDs,and R-CDs possessed bright fluorescence at 425 nm,550 nm,and 640 nm,and photoluminescence quantum yields(PLQYs)of 54.68%,17.93%,and 2.88%,respectively.The structure of SFM-CDs consisted of 5-oxo-3,5-dihydro-2H-thiazolo[3,2-a]pyridine-7-carboxylic acid(TPCA)immobilized on the surface of a carbon core,with the size of the carbon core and degree of disulfide crosslinking between CDs both increasing on going from the B-CDs to the R-CDs,as verified by mechanochromic experiments.The excellent solid-state fluorescence performance of the SFM-CDs allowed their utilization as the fluorescent converter layer in multi-color LEDs and white LEDs with a high color rendering index.展开更多
Hydrogels crosslinked by dynamic covalent bonds can effectively mimic the viscoelastic properties of native extracellular matrix and have been widely explored for 3D cell culture.Disulfide is one of the most common dy...Hydrogels crosslinked by dynamic covalent bonds can effectively mimic the viscoelastic properties of native extracellular matrix and have been widely explored for 3D cell culture.Disulfide is one of the most common dynamic bonds in biological systems whose formation and cleavage are catalyzed by a set of dedicated enzymes.However,in vitro formation of disulfide bonds is a slow process and requires harsh catalysts.Therefore,it is difficult to use disulfide crosslinked hydrogels for cell culture.n this work,we show that disulfide bonds can be formed by thiol-diselenide(Dise)exchange under blue light llumination.This reaction is fast,reversible,and biocompatible.Moreover,residual diselenide in the hydrogel network can also accelerate thiol-disulfide exchange reactions leading to faster cell release from the hydrogels upon the addition of thiol-containing agents.We anticipate that disulfide crosslinked hydrogels catalyzed by diselenide can find broad biomedical applications,such as cell culture,celldelivery,and drug-controlled release.展开更多
The self-assembly prodrugs are usually consisted of drug modules,activation modules,and assembly modules.Keeping the balance between efficacy and safety by selecting suitable modules remains a challenge for developing...The self-assembly prodrugs are usually consisted of drug modules,activation modules,and assembly modules.Keeping the balance between efficacy and safety by selecting suitable modules remains a challenge for developing prodrug nanoassemblies.This study designed four docetaxel(DTX)prodrugs using disulfide bonds as activation modules and different lengths of branched-chain fatty alcohols as assembly modules(C_(16),C_(18),C_(20),and C_(24)).The lengths of the assembly modules determined the self-assembly ability of prodrugs and affected the activation modules’sensitivity.The extension of the carbon chains improved the prodrugs’self-assembly ability and pharmacokinetic behavior while reducing the cytotoxicity and increased cumulative toxicity.The use of C_(20) can balance efficacy and safety.These results provide a great reference for the rational design of prodrug nanoassemblies.展开更多
Autophagy is an important factor in reducing the efficacy of tumor phototherapy(including PTT and PDT).Accurate regulation of autophagy in tumor cells is a new strategy to improve the anti-tumor efficiency of PTT/PDT....Autophagy is an important factor in reducing the efficacy of tumor phototherapy(including PTT and PDT).Accurate regulation of autophagy in tumor cells is a new strategy to improve the anti-tumor efficiency of PTT/PDT.This project intended to construct a tumor-activated autophagy regulator to efficiently block PTT/PDT-induced autophagy and realize synergistic sensitization to tumor phototherapy.To achieve this goal,we first synthesized TRANSFERRIN(Tf)biomimetic mineralized nano-tellurium(Tf-Te)as photosensitizer and then used disulfide bond reconstruction technology to induce Tf-Te self-assembly.The autophagy inhibitor hydroxychloroquine(HCQ)and iron ions carried by Tf were simultaneously loaded to prepare a tumor-responsive drug reservoir Tf-Te/HCQ.After entering breast cancer cells through the“self-guidance system”,Tf-Te/HCQ can generate hyperpyrexia and ROS under NIR laser irradiation,to efficiently induce PTT/PDT effect.Meanwhile,the disulfide bond broke down in response to GSH,and the nanoparticles disintegrated to release Fe2+and HCQ at fixed points.They simultaneously induce lysosomal alkalinization and increased osmotic pressure,effectively inhibit autophagy,and synergistically enhance the therapeutic effect of phototherapy.In vivo anti-tumor results have proved that the tumor inhibition rate of Tf-Te/HCQ can be as high as 88.6%on 4T1 tumor-bearing mice.This multifunctional drug delivery system might provide a new alternative for more precise and effective tumor phototherapy.展开更多
Self-healing polymers based on dynamic crosslinkers have drawn rapidly increasing interest over the last decade.Here,a self-healable epoxy network with exchangeable disulfide bonds was synthesized by polymerizing two ...Self-healing polymers based on dynamic crosslinkers have drawn rapidly increasing interest over the last decade.Here,a self-healable epoxy network with exchangeable disulfide bonds was synthesized by polymerizing two epoxies with an aromatic amine containing a disulfide bond.The bisphenol A diglycidyl ether(DGEBA)and poly(ethylene glycol)diglycidyl ether(DER736)were used as rigid and soft components,respectively.The crosslinking densities of studied polymers decreased with the increasing amount of DER736,resulting in the lower glassy temperature and weaker mechanical strength.The dynamic covalent network character of disulfide bond and its low active energy were also investigated through stress relaxation experiments at various temperatures.The self-healing performance of healable epoxy resins with varied flexibility was measured by tensile tests.The tensile strength of a full-cut sample was restored to 84%(13 MPa)of the initial values(16 MPa)at moderate temperature.Its healed fracture strain was up to 505%.Moreover,the effect of healing time and temperature on the self-healing properties was also studied.A model was proposed to investigate the self-repairing efficiency evolution with healing time,suggesting that hydrogen bonds mainly contributed to the initial sticking or interfacial adhesion while disulfide links and chain interdiffusion assisted time dependent reformation of networks to restore the original mechanical strength.展开更多
Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing,recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages.Here,we study the...Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing,recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages.Here,we study the structure and properties of a new type of thermoplastic polyurethanes(TPUs)with trapped dynamic covalent bonds in the hard-phase domain and report the frustrated relaxation of TPUs containing weak dynamic bond andπ-πinteraction in hard segments.As detected by rheometry,the aromatic TPUs with alkyl disulfide in the hard segments possess the maximum network relaxation time in contrast to those without dynamic bonds and alicyclic TPUs.In situ FTIR and small-angle scattering results reveal that the alkyl disulfide facilitates stronger intermolecular interaction and more stable micro-phase morphology inπ-πinteraction based aromatic TPUs.Molecular dynamics simulation for pure hard segments of model molecules verify that the presence of disulfide bonds leads to strongerπ-πstacking of aromatic rings due to both enhanced assembling thermodynamics and kinetics.The enhancedπ-πpacking and micro-phase structure in TPUs further kinetically immobilize the dynamic bond.This kinetically interlocking between the weak dynamic bonds and strong molecular interaction in hard segments leads to much slower network relaxation of TPU.This work provides a new insight in tuning the network relaxation and heat resistance as well as molecular self-assembly in stimulus-responsive dynamic polymers by both molecular design and micro-phase control toward the functional applications of advanced materials.展开更多
Cysteine chemistry provides a low cost and convenient way for site-specific protein modification.However,recombinant expression of disulfide bonding containing protein with unpaired cysteine is technically challenging...Cysteine chemistry provides a low cost and convenient way for site-specific protein modification.However,recombinant expression of disulfide bonding containing protein with unpaired cysteine is technically challenging and the resulting protein often suffers from significantly reduced yield and activity.Here we used genetic code expansion technique to introduce a surface exposed self-paired dithiol functional group into proteins,which can be selectively reduced to afford active thiols.Two compounds containing self-paired disulfides were synthesized,and their genetic incorporations were validated using green fluorescent proteins(GFP).The compatibility of these self-paired di-thiols with natural disulfide bond was demonstrated using antibody fragment to afford site-specifically labeled antibody.This work provides another valuable building block into the chemical tool-box for site-specific labeling of proteins containing internal disulfides.展开更多
The content of biothiols in cells is highly associated with the occurrence and development of several diseases.However,due to their active chemical properties,thiol-contained molecules are normally volatile during the...The content of biothiols in cells is highly associated with the occurrence and development of several diseases.However,due to their active chemical properties,thiol-contained molecules are normally volatile during the detection process,rendering precise analysis of intracellular biothiols challenging.In this study,5,5’-dithiobis-(2-nitrobenzoic acid)(DTNB)is covalently modified on the surface of gold nanorods(AuNRs),constructing sensing substrates for in situ Raman imaging analysis of biothiols in cells.Au NRs are able to serve as ideal surface-enhanced Raman scattering substrates,and thus Raman signals of DTNB are greatly amplified by AuNRs.Meanwhile,the disulfide bond of DTNB can be broken by thiols,thereby releasing part of DTNB from the surface of AuNRs.As a result,three kinds of main biothiols are sensitively quantified with DTNB-modified AuNRs according to the variation of Raman signals,and DTNB-modified Au NRs exhibit far better analytical performance than a commercial probe.In addition,the sensing substrates can be readily delivered to cytoplasm with the transmembrane of Au NRs,and are capable of responding to biothiols in cells.Notably,the Raman approach is established by the breaking of chemical bonds rather than the aggregation of substrates,which is more inclined to analyze intracellular biothiols with a desirable spatial resolution.Therefore,fluctuation of biothiols in glioma cells is evidently observed via Raman imaging.Overall,this work provides an alternative strategy for designing Raman sensors to visualize active molecules in cells.展开更多
基金supported by R&D Program of Power Batteries with Low Temperature and High Energy,Science and Technology Bureau of Changchun(19SS013)Key Subject Construction of Physical Chemistry of Northeast Normal University+1 种基金the Fundamental Research Funds for the Central Universities(2412020FZ007,2412020FZ008)National Natural Science Foundation of China(22102020)
文摘The self-healing solid polymer electrolytes(SHSPEs)can spontaneously eliminate mechanical damages or micro-cracks generated during the assembly or operation of lithium-ion batteries(LIBs),significantly improving cycling performance and extending service life of LIBs.Here,we report a novel cross-linked network SHSPE(PDDP)containing hydrogen bonds and dynamic disulfide bonds with excellent self-healing properties and nonflammability.The combination of hydrogen bonding between urea groups and the metathesis reaction of dynamic disulfide bonds endows PDDP with rapid self-healing capacity at 28°C without external stimulation.Furthermore,the addition of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide(EMIMTFSI)improves the ionic conductivity(1.13×10^(−4)S cm^(−1)at 28°C)and non-flammability of PDDP.The assembled Li/PDDP/LiFePO_(4)cell exhibits excellent cycling performance with a discharge capacity of 137 mA h g^(−1)after 300 cycles at 0.2 C.More importantly,the self-healed PDDP can recover almost the same ionic conductivity and cycling performance as the original PDDP.
基金Supported by the National Key Research and Development Plan of China(2019YFC1905902,2019YFC1905900)Key Research and Development Plan in Shandong Province(2020CXGC010603,2021ZDSYS10,2022CXGC020206)+2 种基金"Open Competition Mechanism"Project of Qilu University of Technology(Shandong Academy of Sciences)(2022JBZ01-06)Taishan Industry Leading Talent Program(tscy20180103)National Natural Science Foundation of China(31801527)。
文摘Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.
基金supported by the National Natural Science Foundation of China(No.51873110)the Foundation of Guangdong Provincial Key Laboratory of Natural Rubber Processing and Key Laboratory of Carb on Fiber and Functio nal Polymers(Beijing University of Chemical Technology),Ministry of Educati on.
文摘Elastomers with outstanding strength,toughness and healing efficiency are highly promising for many emerging fields.However,it is still a challenge to integrate all these beneficial features in one elastomer.Herein,an asymmetric alicyclic structure adjacent to aromatic disulfide was tactfully introduced into the backbone of polyurethane(PU)elastomer.Specifically,such elastomer(PU-HPS)was fabricated by polycondensing polytetramethylene ether glycol(PTMEG),isophorone diisocyanate(IPDI)and p-hydroxydiphenyl disulfide(HPS)via one-pot method.The molecular mobility and phase morphology of PU-HPS can be tuned by adjusting the HPS content.Consequently,the dynamic exchange of hydrogen and disulfide bonds in the hard segment domains can also be tailored.The optimized sample manifests outstanding tensile strength(46.4 MPa),high toughness(109.1 MJ/m^(3)),high self-healing efficiency after fracture(90.3%),complete scratch recovery(100%)and good puncture resistance.Therefore,this work provides a facile strategy for developing robust self-healing polymers.
基金the financial support of the research fund of the Science and Technology Innovation Program of Hunan Province(2020RC2076)the General Project of Education Department of Hunan Province(21C008)+2 种基金the Open Research Fund of School of Chemistry and Chemical Engineering,Henan Normal University(2022C02)the Youth Science and Technology Talent Project of Hunan Province(2022RC1197)the Hunan Provincial Natural Science Foundation of China(2021JJ40529)。
文摘Combining photocatalytic organic reactions with CO_(2)reduction is an efficient solar energy utilization mode,but it is still limited by the organic species that can be matched and the low conversion.Herein,ultrathin organic polymer with p-πconjugated structure(TPP)was rationally designed and prepared,and showed a high yield of CO(15.2 mmol g^(-1))and conversion of SAS coupled products(100%),far exceeding the organic polymer with P=O structure.The enhanced photoredox activity of TPP is ascribed to the orbital interaction between the p-orbital on phosphorus and theπ-orbitals of aromatic,which can accelerate the photoinduced charge carrier separation and improve the CO_(2)adsorption capacity.TPP can also be used for the dehydrocoupling of various benzyl mercaptans to the corresponding SAS bond products.This work provides a new concept for the efficient synthesis of disulfide bonds combined with CO_(2)reduction in a photoreaction system.
基金supported by National Natural Science Foundation of China(No.82173766,82104109)Natural Science Foundation of Liaoning Province(2022-BS158)+1 种基金Liaoning Province Applied Basic Research Program(No.2022JH2/101300097)National Key R&D Program of China(No.2022YFE0111600).
文摘The disulfide bond plays a crucial role in the design of anti-tumor prodrugs due to its exceptional tumor-specific redox responsiveness. However, premature breaking of disulfide bonds is triggered by small amounts of reducing substances (e.g., ascorbic acid, glutathione, uric acid and tea polyphenols) in the systemic circulation. This may lead to toxicity, particularly in oral prodrugs that require more frequent and high-dose treatments. Fine-tuning the activation kinetics of these prodrugs is a promising prospect for more efficient on-target cancer therapies. In this study, disulfide, steric disulfide, and ester bonds were used to bridge cabazitaxel (CTX) to an intestinal lymph vessel-directed triglyceride (TG) module. Then, synthetic prodrugs were efficiently incorporated into self-nanoemulsifying drug delivery system (corn oil and Maisine CC were used as the oil phase and Cremophor EL as the surfactant). All three prodrugs had excellent gastric stability and intestinal permeability. The oral bioavailability of the disulfide bond-based prodrugs (CTX-(C)S-(C)S-TG and CTX-S-S-TG) was 11.5- and 19.1-fold higher than that of the CTX solution, respectively, demonstrating good oral delivery efficiency. However, the excessive reduction sensitivity of the disulfide bond resulted in lower plasma stability and safety of CTX-S-S-TG than that of CTX-(C)S-(C)S-TG. Moreover, introducing steric hindrance into disulfide bonds could also modulate drug release and cytotoxicity, significantly improving the anti-tumor activity even compared to that of intravenous CTX solution at half dosage while minimizing off-target adverse effects. Our findings provide insights into the design and fine-tuning of different disulfide bond-based linkers, which may help identify oral prodrugs with more potent therapeutic efficacy and safety for cancer therapy.
基金financially supported by National Nature Science Foundation of China(No.81872816,81703451)Liaoning Revitalization Talents Program,No XLYC1808017+2 种基金Key projects of Technology bureau in Shenyang,No18400408Key projects of Liaoning Province Department of Education,No.2017LZD03supported by Heilongjiang Provincial Key Laboratory of Plant Genetic Engineering and Biological Fermentation Engineering for Cold Region。
文摘One of the major barriers in utilizing prodrug nanocarriers for cancer therapy is the slow release of parent drug in tumors.Tumor cells generally display the higher oxidative level than normal cells,and also displayed the heterogeneity in terms of redox homeostasis level.We previously found that the disulfide bond-linkage demonstrates surprising oxidationsensitivity to form the hydrophilic sulfoxide and sulphone groups.Herein,we develop oxidation-strengthened prodrug nanosystem loaded with pyropheophorbide a(PPa)to achieve light-activatable cascade drug release and enhance therapeutic efficacy.The disulfide bond-driven prodrug nanosystems not only respond to the redox-heterogeneity in tumor,but also respond to the exogenous oxidant(singlet oxygen)elicited by photosensitizers.Once the prodrug nanoparticles(NPs)are activated under irradiation,they would undergo an oxidative self-strengthened process,resulting in a facilitated drug cascade release.The IC50 value of the PPa@PTX-S-S NPs without irradiation was 2-fold higher than those of NPs plus irradiation.In vivo,the PPa@PTX prodrug NPs display prolonged systemic circulation and increased accumulation in tumor site.The PPa@PTXS-S NPs showed much higher efficiency than free PTX or the PPa@PTX-C-C NPs to suppress the growth of 4 T1 tumors.Therefore,this novel oxidation-strengthened disulfide-bridged prodrug-nanosystem has a great potential in the enhanced efficacy of cancer synergetic photochemotherapy.
基金funding from the National Natural Science Foundation of China(No.81703451 and 81773656)the Excellent Youth Science Foundation of Liaoning Province(No.2020-YQ-06)+2 种基金the Liaoning Revitalization Talents Program(No.XLYC1808017 and XLYC1907129)the China Postdoctoral Science Foundation(No.2020M670794)the Science and Technology Major Project of Liaoning(No.2019JH1/10300004)。
文摘Disulfide bond-bridging strategy has been extensively utilized to construct tumor specificity-responsive aliphatic prodrug nanoparticles(PNPs) for precise cancer therapy. Yet, there is no research shedding light on the impacts of the saturation and cis-trans configuration of aliphatic tails on the self-assembly capacity of disulfide bond-linked prodrugs and the in vivo delivery fate of PNPs. Herein, five disulfide bond-linked docetaxelfatty acid prodrugs are designed and synthesized by using stearic acid, elaidic acid, oleic acid, linoleic acid and linolenic acid as the aliphatic tails, respectively. Interestingly, the cistrans configuration of aliphatic tails significantly influences the self-assembly features of prodrugs, and elaidic acid-linked prodrug with a trans double bond show poor self-assembly capacity. Although the aliphatic tails have almost no effect on the redox-sensitive drug release and cytotoxicity, different aliphatic tails significantly influence the chemical stability of prodrugs and the colloidal stability of PNPs, thus affecting the in vivo pharmacokinetics, biodistribution and antitumor efficacy of PNPs. Our findings illustrate how aliphatic tails affect the assembly characteristic of disulfide bond-linked aliphatic prodrugs and the in vivo delivery fate of PNPs, and thus provide theoretical basis for future development of disulfide bond-bridged aliphatic prodrugs.
基金supported by China Postdoctoral Science Foundation Grant(2019M661742).
文摘Enhancing the stability of biomolecules is one of the hot topics in industry.In this study,we enhanced the stability of an important protein called LEPTIN.LEPTIN is a hormone secreted by fat cells playing an essential role in body weight and composition,and its deficiency can result in several disorders.The treatment of related LEPTIN dysfunctions is often available in the form of injection.To decrease the cost and the frequency of its applications can be achieved by increasing its lifetime through engineering LEPTIN.In this study,to engineer LEPTIN,we have introduced disulfide bonds.Disulfide By Design server was used to predict the suitable nominate pairs,which suggested three pairs of amino acids to be mutated to cysteine for disulfide bond formation.Additionally,to further evaluate the effect of combined mutations,we combined these three nominated pairs to produce three more mutants.In order to assess the effect of introduced mutations,molecular dynamic(MD)simulation was performed.The result suggests that Mutant-1 is more stable in comparison to wild-type and the other mutants.Moreover,docking results showed that the introduced mutation does not affect the receptor binding performance;therefore,it can be considered a suitable choice for future protein engineering.
文摘A prediction method of protein disulfide bond based on support vector machine and sample selection is proposed in this paper. First, the protein sequences selected are en-coded according to a certain encoding, input data for the prediction model of protein disulfide bond is generated;Then sample selection technique is used to select a portion of input data as training samples of support vector machine;finally the prediction model training samples trained is used to predict protein disulfide bond. The result of simulation experiment shows that the prediction model based on support vector ma-chine and sample selection can increase the prediction accuracy of protein disulfide bond.
基金supported by the National Key Research and Development Program of China(Nos.2021YFA0910601 and 2021YFC2100203)Shanghai Municipal Education Commission(2021-03-52)Science and Technology Research Program of Shanghai(19DZ2282100).
文摘Kluyveromyces marxianus is a food-safe yeast with great potential for producing heterologous proteins.Improving the yield in K.marxianus remains a challenge and incorporating large-scale functional modules poses a technical obstacle in engineering.To address these issues,linear and circular yeast artificial chromosomes of K.marxianus(KmYACs)were constructed and loaded with disulfide bond formation modules from Pichia pastoris or K.marxianus.These modules contained up to seven genes with a maximum size of 15 kb.KmYACs carried telomeres either from K.marxianus or Tetrahymena.KmYACs were transferred successfully into K.marxianus and stably propagated without affecting the normal growth of the host,regardless of the type of telomeres and configurations of KmYACs.KmYACs increased the overall expression levels of disulfide bond formation genes and significantly enhanced the yield of various heterologous proteins.In high-density fermentation,the use of KmYACs resulted in a glucoamylase yield of 16.8 g/l,the highest reported level to date in K.marxianus.Transcriptomic and metabolomic analysis of cells containing KmYACs suggested increased flavin adenine dinucleotide biosynthesis,enhanced flux entering the tricarboxylic acid cycle,and a preferred demand for lysine and arginine as features of cells overexpressing heterologous proteins.Consistently,supplementing lysine or arginine further improved the yield.Therefore,KmYAC provides a powerful platform for manipulating large modules with enormous potential for industrial applications and fundamental research.Transferring the disulfide bond formation module via YACs proves to be an efficient strategy for improving the yield of heterologous proteins,and this strategy may be applied to optimize other microbial cell factories.
文摘Neuregulin plays an important role in heart structure and function.Research discovered that recombinant neuregulin could reduce the degree of damage on myocardial cells caused by ischemia,hypoxia and viral infection.The primary structure,including N-terminal sequence,C-terminal sequence,PMF,accurate molecular mass,and disulfide bonding pattern of recombinant human neuregulin,have been identified by ESI-Q-TOF MS,Autoflex MALDI-TOF MS,9.4T Apex Q-FT MS and Ultraflex Ⅲ MALDI-TOF/TOF combining with two e]ymatic digestion.A abnormal peptide impurity in this drug was found and sequenced by Q-TOF MS and TOF/TOF MS,this is useful for the product quanlity control.
文摘The reaction of bis-[2-amino-4-pheny1-5-thiazolyl] disulfide with 5-nitro-salicylaldehyde in absolute ethanol resulted in the formation of a new Schiff base ligand H<sub>2</sub>L (1). Characterization of the ligand was performed by FT-IR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, UV-Vis, elemental analysis and single crystal X-ray diffraction. The ligand, (1), possesses a disulfide –S–S– bridge of 2.1121 (3) ? length, and the molecule adopts a cis-conformation around this bond. In the crystal structure of (1), an intramolecular O–H···N hydrogen bond with D… A distance of 2.69 (3) ? was present. The reaction of (1) with Co(NO<sub>3</sub>)<sub>2</sub>·6H<sub>2</sub>O and CuCl<sub>2</sub>·2H<sub>2</sub>O in methanol afforded the corresponding metal complexes. The obtained solids were further investigated by elemental analysis and UV-Vis titration that confirmed the formation of [CoL] and [ClCuHL] complexes. However, recrystallizaion of the Co(II) complex in dimethylsulfoxide caused the complete hydrolysis of the imine bond and afforded a Co(II) complex in which two 5-nitro-salicylaldehyde and two DMSO molecules were coordinated to the central metal in an octahedral fashion. This structure (2) was also confirmed by single crystal X-ray analysis.
基金supported by the National Natural Science Foundation of China(52122308,21905253,51973200,52203244,21725304)the Natural Science Foundation of Henan Province(202300410372)the China Postdoctoral Science Foundation(2022M712868).
文摘Solid-state fluorescent multi-color carbon dots(SFM-CDs),prepared using the same precursor(s)without the need for dispersion in a solid matrix,are highly demanded for a wide range of applications.Herein,we report a microwave-assisted strategy for the prepara-tion of SFM-CDs with blue,yellow and red emissions within 5 min from the same precursors.The as-prepared B-CDs,Y-CDs,and R-CDs possessed bright fluorescence at 425 nm,550 nm,and 640 nm,and photoluminescence quantum yields(PLQYs)of 54.68%,17.93%,and 2.88%,respectively.The structure of SFM-CDs consisted of 5-oxo-3,5-dihydro-2H-thiazolo[3,2-a]pyridine-7-carboxylic acid(TPCA)immobilized on the surface of a carbon core,with the size of the carbon core and degree of disulfide crosslinking between CDs both increasing on going from the B-CDs to the R-CDs,as verified by mechanochromic experiments.The excellent solid-state fluorescence performance of the SFM-CDs allowed their utilization as the fluorescent converter layer in multi-color LEDs and white LEDs with a high color rendering index.
基金This work is funded by the National Key R&D Program of China(Grant No.2020YFA0908100)the National Natural Science Foundation of China(Nos.11934008,11974174 and 12002149)the Research Project of Jinan Microecological Biomedicine Shandong Laboratory。
文摘Hydrogels crosslinked by dynamic covalent bonds can effectively mimic the viscoelastic properties of native extracellular matrix and have been widely explored for 3D cell culture.Disulfide is one of the most common dynamic bonds in biological systems whose formation and cleavage are catalyzed by a set of dedicated enzymes.However,in vitro formation of disulfide bonds is a slow process and requires harsh catalysts.Therefore,it is difficult to use disulfide crosslinked hydrogels for cell culture.n this work,we show that disulfide bonds can be formed by thiol-diselenide(Dise)exchange under blue light llumination.This reaction is fast,reversible,and biocompatible.Moreover,residual diselenide in the hydrogel network can also accelerate thiol-disulfide exchange reactions leading to faster cell release from the hydrogels upon the addition of thiol-containing agents.We anticipate that disulfide crosslinked hydrogels catalyzed by diselenide can find broad biomedical applications,such as cell culture,celldelivery,and drug-controlled release.
基金financially supported by National Key R&D Program of China(No.2022YFE0111600)National Natural Science Foundation of China(No.82272151 and 82204318)+2 种基金Doctoral Scientific Research Staring Foundation of Liaoning Province(No.2021-BS-130,China)General Program of Department of Education of Liaoning Province(No.LJKZ0953,China)Shenyang Young and Middle-aged Science and Technology Innovation Talents Support Program(RC220389,China)。
文摘The self-assembly prodrugs are usually consisted of drug modules,activation modules,and assembly modules.Keeping the balance between efficacy and safety by selecting suitable modules remains a challenge for developing prodrug nanoassemblies.This study designed four docetaxel(DTX)prodrugs using disulfide bonds as activation modules and different lengths of branched-chain fatty alcohols as assembly modules(C_(16),C_(18),C_(20),and C_(24)).The lengths of the assembly modules determined the self-assembly ability of prodrugs and affected the activation modules’sensitivity.The extension of the carbon chains improved the prodrugs’self-assembly ability and pharmacokinetic behavior while reducing the cytotoxicity and increased cumulative toxicity.The use of C_(20) can balance efficacy and safety.These results provide a great reference for the rational design of prodrug nanoassemblies.
基金This work was supported by the National Natural Science Foundation of China(Nos.82102918,81972893 and 82172719)the Key Program for Science and Technology Research in Henan Province(No.232102311093,China)the Training Plan for Young Backbone Teachers in Higher Education Institutions of Henan Province(No.2021ZDGGJS054,China).
文摘Autophagy is an important factor in reducing the efficacy of tumor phototherapy(including PTT and PDT).Accurate regulation of autophagy in tumor cells is a new strategy to improve the anti-tumor efficiency of PTT/PDT.This project intended to construct a tumor-activated autophagy regulator to efficiently block PTT/PDT-induced autophagy and realize synergistic sensitization to tumor phototherapy.To achieve this goal,we first synthesized TRANSFERRIN(Tf)biomimetic mineralized nano-tellurium(Tf-Te)as photosensitizer and then used disulfide bond reconstruction technology to induce Tf-Te self-assembly.The autophagy inhibitor hydroxychloroquine(HCQ)and iron ions carried by Tf were simultaneously loaded to prepare a tumor-responsive drug reservoir Tf-Te/HCQ.After entering breast cancer cells through the“self-guidance system”,Tf-Te/HCQ can generate hyperpyrexia and ROS under NIR laser irradiation,to efficiently induce PTT/PDT effect.Meanwhile,the disulfide bond broke down in response to GSH,and the nanoparticles disintegrated to release Fe2+and HCQ at fixed points.They simultaneously induce lysosomal alkalinization and increased osmotic pressure,effectively inhibit autophagy,and synergistically enhance the therapeutic effect of phototherapy.In vivo anti-tumor results have proved that the tumor inhibition rate of Tf-Te/HCQ can be as high as 88.6%on 4T1 tumor-bearing mice.This multifunctional drug delivery system might provide a new alternative for more precise and effective tumor phototherapy.
基金the Natural Science Foundation of Jiangxi Education Department(No.GJJ170680)the National Natural Science Foundation of China(Nos.51963010,21867011,and 51563011).
文摘Self-healing polymers based on dynamic crosslinkers have drawn rapidly increasing interest over the last decade.Here,a self-healable epoxy network with exchangeable disulfide bonds was synthesized by polymerizing two epoxies with an aromatic amine containing a disulfide bond.The bisphenol A diglycidyl ether(DGEBA)and poly(ethylene glycol)diglycidyl ether(DER736)were used as rigid and soft components,respectively.The crosslinking densities of studied polymers decreased with the increasing amount of DER736,resulting in the lower glassy temperature and weaker mechanical strength.The dynamic covalent network character of disulfide bond and its low active energy were also investigated through stress relaxation experiments at various temperatures.The self-healing performance of healable epoxy resins with varied flexibility was measured by tensile tests.The tensile strength of a full-cut sample was restored to 84%(13 MPa)of the initial values(16 MPa)at moderate temperature.Its healed fracture strain was up to 505%.Moreover,the effect of healing time and temperature on the self-healing properties was also studied.A model was proposed to investigate the self-repairing efficiency evolution with healing time,suggesting that hydrogen bonds mainly contributed to the initial sticking or interfacial adhesion while disulfide links and chain interdiffusion assisted time dependent reformation of networks to restore the original mechanical strength.
基金financially supported by the National Natural Science Foundation of China(No.21774135)。
文摘Stimulus-responsive polymers containing dynamic bonds enable fascinating properties of self-healing,recycling and reprocessing due to enhanced relaxation of polymer chain/network with labile linkages.Here,we study the structure and properties of a new type of thermoplastic polyurethanes(TPUs)with trapped dynamic covalent bonds in the hard-phase domain and report the frustrated relaxation of TPUs containing weak dynamic bond andπ-πinteraction in hard segments.As detected by rheometry,the aromatic TPUs with alkyl disulfide in the hard segments possess the maximum network relaxation time in contrast to those without dynamic bonds and alicyclic TPUs.In situ FTIR and small-angle scattering results reveal that the alkyl disulfide facilitates stronger intermolecular interaction and more stable micro-phase morphology inπ-πinteraction based aromatic TPUs.Molecular dynamics simulation for pure hard segments of model molecules verify that the presence of disulfide bonds leads to strongerπ-πstacking of aromatic rings due to both enhanced assembling thermodynamics and kinetics.The enhancedπ-πpacking and micro-phase structure in TPUs further kinetically immobilize the dynamic bond.This kinetically interlocking between the weak dynamic bonds and strong molecular interaction in hard segments leads to much slower network relaxation of TPU.This work provides a new insight in tuning the network relaxation and heat resistance as well as molecular self-assembly in stimulus-responsive dynamic polymers by both molecular design and micro-phase control toward the functional applications of advanced materials.
基金financially supported by National Key Research and Development Program of China (No.2016YFA0201400)the National Natural Science Foundation of China (No.21778005)+1 种基金Peking University Health Science Center (Nos.BMU20160537 andBMU2017QQ006)the Youth Thousand-Talents Program of China for support
文摘Cysteine chemistry provides a low cost and convenient way for site-specific protein modification.However,recombinant expression of disulfide bonding containing protein with unpaired cysteine is technically challenging and the resulting protein often suffers from significantly reduced yield and activity.Here we used genetic code expansion technique to introduce a surface exposed self-paired dithiol functional group into proteins,which can be selectively reduced to afford active thiols.Two compounds containing self-paired disulfides were synthesized,and their genetic incorporations were validated using green fluorescent proteins(GFP).The compatibility of these self-paired di-thiols with natural disulfide bond was demonstrated using antibody fragment to afford site-specifically labeled antibody.This work provides another valuable building block into the chemical tool-box for site-specific labeling of proteins containing internal disulfides.
基金supported by the National Natural Science Foundation of China(22234005,21974070,22222407,22176099)the Natural Science Foundation of Jiangsu Province(BK20192008)the State Key Laboratory of Analytical Chemistry for Life Science(SKLACLS2220)。
文摘The content of biothiols in cells is highly associated with the occurrence and development of several diseases.However,due to their active chemical properties,thiol-contained molecules are normally volatile during the detection process,rendering precise analysis of intracellular biothiols challenging.In this study,5,5’-dithiobis-(2-nitrobenzoic acid)(DTNB)is covalently modified on the surface of gold nanorods(AuNRs),constructing sensing substrates for in situ Raman imaging analysis of biothiols in cells.Au NRs are able to serve as ideal surface-enhanced Raman scattering substrates,and thus Raman signals of DTNB are greatly amplified by AuNRs.Meanwhile,the disulfide bond of DTNB can be broken by thiols,thereby releasing part of DTNB from the surface of AuNRs.As a result,three kinds of main biothiols are sensitively quantified with DTNB-modified AuNRs according to the variation of Raman signals,and DTNB-modified Au NRs exhibit far better analytical performance than a commercial probe.In addition,the sensing substrates can be readily delivered to cytoplasm with the transmembrane of Au NRs,and are capable of responding to biothiols in cells.Notably,the Raman approach is established by the breaking of chemical bonds rather than the aggregation of substrates,which is more inclined to analyze intracellular biothiols with a desirable spatial resolution.Therefore,fluctuation of biothiols in glioma cells is evidently observed via Raman imaging.Overall,this work provides an alternative strategy for designing Raman sensors to visualize active molecules in cells.