Constrained peptide scaffolds that are tolerant to extensive sequence manipulation and amenable to bioactive peptide design are of great value to the development of novel protein binders and peptide therapeutics. In t...Constrained peptide scaffolds that are tolerant to extensive sequence manipulation and amenable to bioactive peptide design are of great value to the development of novel protein binders and peptide therapeutics. In this work, we reported strategies for the design and synthesis of a kind of novel interchain doubly-bridged α-helical peptides, involving mutual stabilization of two peptide α-helices linked by two interchain bisthioether crosslinkers. By taking a MDM2-binding peptide with an α-helical tendency as a model, we demonstrated that α-helical dimers with significantly improved structural and proteolytic stability and nanomolar binding affinity to the target protein can be obtained. By modulating the surface charges on the dimeric peptides, we also obtained a dimeric peptide with enhanced cellpenetrating capability, which can efficiently penetrate into cancer cells and inhibit the intracellular MDM2-p53 interactions to promote cell apoptosis. Considering that many proteins take a surface α-helical segment as the binding motif to mediate their interactions with other proteins, we believe that our interchain doubly-bridged α-helical peptides would provide a promising scaffold for the development of novel high-affinity protein binders.展开更多
Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-...Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].展开更多
MicroRNA-208a(miR-208a)plays critical roles in the severe fibrosis and heart failure post myocardial ischemia/reperfusion(IR)injury.MiR-208a inhibitor(mI)with complementary RNA sequence can silence the expression of m...MicroRNA-208a(miR-208a)plays critical roles in the severe fibrosis and heart failure post myocardial ischemia/reperfusion(IR)injury.MiR-208a inhibitor(mI)with complementary RNA sequence can silence the expression of miR-208a,while it is challenging to achieve efficient and myocardium-targeted delivery.Herein,biomimetic nanocomplexes(NCs)reversibly coated with red blood cell membrane(RM)were developed for the myocardial delivery of mI.To construct the NCs,membrane-penetrating helical polypeptide(PG)was first adopted to condense mI and form the cationic inner core,which subsequently adsorbed catalase(CAT)via electrostatic interaction followed by surface coating with RM.The membrane-coated NCs enabled prolonged blood circulation after systemic administration,and could accumulate in the injured myocardium via passive targeting.In the oxidative microenvironment of injured myocardium,CAT decomposed H_(2)O_(2)to produce O_(2)bubbles,which drove the shedding of the outer RM to expose the positively charged inner core,thus facilitated effective internalization by cardiac cells.Based on the combined contribution of mI-mediated miR-208a silencing and CAT-mediated alleviation of oxidative stress,NCs effectively ameliorated the myocardial microenvironment,hence reducing the infarct size as well as fibrosis and promoting recovery of cardiac functions.This study provides an effective strategy for the cytosolic delivery of nucleic acid cargoes in the myocardium,and it renders an enlightened approach to resolve the blood circulation/cell internalization dilemma of cell membrane-coated delivery systems.展开更多
HYL derived from the venom of the solitary bee Hylaeus signatus(Hymenoptera:Colletidae)is anα-helical antimicrobial peptide with 16 residues.To explore whether HYL can be applied in anti-tumor therapy,we synthesized ...HYL derived from the venom of the solitary bee Hylaeus signatus(Hymenoptera:Colletidae)is anα-helical antimicrobial peptide with 16 residues.To explore whether HYL can be applied in anti-tumor therapy,we synthesized HYL and further modified its structure by using a solid-phase synthesis method,and then evaluated their antitumor activities.Firstly,we identified the key residues of HYL by alanine scanning strategy,and then a series of stapled peptides were synthesized by hydrocarbon stapling strategy without destroying the key residues.All the stapled peptides of HYL showed significant improvement not only inα-helicity,but also in antitumor activity and protease resistance when compared to the parent peptide HYL.The results showed that hydrophobicity and amphiphilicity are important factors affecting the antitumor activity of HYL,and the stapling strategy can significantly affect the proteolytic stability and helicity of HYL.What’s more,we find that the stapled peptides HYL-14,HYL-16 and HYL-18 show a promising prospect for novel anti-tumor drug development.展开更多
基金financial support from the National Natural Science Foundation of China (Nos. 21675132 and 21822404)the Program for Changjiang Scholars and Innovative Research Team in University (No. 13036)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 21521004)
文摘Constrained peptide scaffolds that are tolerant to extensive sequence manipulation and amenable to bioactive peptide design are of great value to the development of novel protein binders and peptide therapeutics. In this work, we reported strategies for the design and synthesis of a kind of novel interchain doubly-bridged α-helical peptides, involving mutual stabilization of two peptide α-helices linked by two interchain bisthioether crosslinkers. By taking a MDM2-binding peptide with an α-helical tendency as a model, we demonstrated that α-helical dimers with significantly improved structural and proteolytic stability and nanomolar binding affinity to the target protein can be obtained. By modulating the surface charges on the dimeric peptides, we also obtained a dimeric peptide with enhanced cellpenetrating capability, which can efficiently penetrate into cancer cells and inhibit the intracellular MDM2-p53 interactions to promote cell apoptosis. Considering that many proteins take a surface α-helical segment as the binding motif to mediate their interactions with other proteins, we believe that our interchain doubly-bridged α-helical peptides would provide a promising scaffold for the development of novel high-affinity protein binders.
基金supported by CAPES/PROEX,FAPESP(2010/10936-5)A.F.Donatti has a doctorate scholarship from CAPESC.R.A.Leite-Panissi also received grants from the CNPq(Grant No.307383/2012-1).
文摘Corticotropin-releasing factor (CRF) is a peptide that is released from the hypothalamus into widespread areas of the brain. Evidence has suggested that CRF is involved as a neuromodulator outside of the hypothalamic-pituitary-adrenal axis, playing an important role in fear, anxiety, depression and pain modulation. Our previous report demonstrated that CRF receptor activation in basolateral (BLA) or central nuclei of the amygdala (CeA) produces innate fear in guinea pigs. Inhibition of these receptors via administration of α-helical CRF9-41 (a nonspecific antagonist) into the CeA or BLA decreased innate fear behavior [1]. Additionally, there is strong evidence that emotional behavior and nociception can be modulated simultaneously. The present study was conducted to investigate the involvement of the CRF receptors of the BLA or CeA in nociception in guinea pigs. Guinea pigs were treated with CRF and α-helical CRF>9-41> in three different doses or injected with α-helical CRF9-41 preceded by CRF into the BLA or CeA, and they were evaluated using the hot plate test. Our findings indicated that activation of CRF receptors in the BLA and in the CeA promoted antinociception, and this effect was reversed by preadministration of α-helical CRF9-41 in the same area. The treatment with α-helical CRF>9-41> per se into the BLA and CeA did not alter nociception. Thus, nociception modulation occurs in a phasic manner, whereas defensive behavior can occur tonically because the α-helical CRF9-41 did not cause any modification on the index of analgesia in the hot plate test but did reduce innate fear behavior [1].
基金supported by the National Natural Science Foundation of China(Nos.82172076,52273144,and 52033006)111 project,Collaborative Innovation Center of Suzhou Nano Science&Technology,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,and Suzhou Key Laboratory of Nanotechnology and Biomedicine.
文摘MicroRNA-208a(miR-208a)plays critical roles in the severe fibrosis and heart failure post myocardial ischemia/reperfusion(IR)injury.MiR-208a inhibitor(mI)with complementary RNA sequence can silence the expression of miR-208a,while it is challenging to achieve efficient and myocardium-targeted delivery.Herein,biomimetic nanocomplexes(NCs)reversibly coated with red blood cell membrane(RM)were developed for the myocardial delivery of mI.To construct the NCs,membrane-penetrating helical polypeptide(PG)was first adopted to condense mI and form the cationic inner core,which subsequently adsorbed catalase(CAT)via electrostatic interaction followed by surface coating with RM.The membrane-coated NCs enabled prolonged blood circulation after systemic administration,and could accumulate in the injured myocardium via passive targeting.In the oxidative microenvironment of injured myocardium,CAT decomposed H_(2)O_(2)to produce O_(2)bubbles,which drove the shedding of the outer RM to expose the positively charged inner core,thus facilitated effective internalization by cardiac cells.Based on the combined contribution of mI-mediated miR-208a silencing and CAT-mediated alleviation of oxidative stress,NCs effectively ameliorated the myocardial microenvironment,hence reducing the infarct size as well as fibrosis and promoting recovery of cardiac functions.This study provides an effective strategy for the cytosolic delivery of nucleic acid cargoes in the myocardium,and it renders an enlightened approach to resolve the blood circulation/cell internalization dilemma of cell membrane-coated delivery systems.
基金supported by NSFC-Shandong Joint Fund(No.U1606403)Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)。
文摘HYL derived from the venom of the solitary bee Hylaeus signatus(Hymenoptera:Colletidae)is anα-helical antimicrobial peptide with 16 residues.To explore whether HYL can be applied in anti-tumor therapy,we synthesized HYL and further modified its structure by using a solid-phase synthesis method,and then evaluated their antitumor activities.Firstly,we identified the key residues of HYL by alanine scanning strategy,and then a series of stapled peptides were synthesized by hydrocarbon stapling strategy without destroying the key residues.All the stapled peptides of HYL showed significant improvement not only inα-helicity,but also in antitumor activity and protease resistance when compared to the parent peptide HYL.The results showed that hydrophobicity and amphiphilicity are important factors affecting the antitumor activity of HYL,and the stapling strategy can significantly affect the proteolytic stability and helicity of HYL.What’s more,we find that the stapled peptides HYL-14,HYL-16 and HYL-18 show a promising prospect for novel anti-tumor drug development.