Lysozyme(EC3.2.1.17)plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genom...Lysozyme(EC3.2.1.17)plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genome-wide association analysis,the g-type lysozyme gene,which is named NaLyg in yellow drum(Nibea albiflora),was found to be a key candidate gene for disease resistance in response to Vibrio harveyi infection.The cDNA of NaLyg was 1025 bp,including four exons and three introns,and its open reading frame(ORF)had a full-length of 582 bp,encoding 193 amino acids.NaLyg was found to be conserved during evolution through bioinformatic analyses.The NaLyg protein possessed a sugar binding domain and three catalytic sites,including Glu71,Asp84 and Asp101.Quantitative qRT-PCR results confirmed that NaLyg gene mRNA was visibly increased after V.harveyi infection.The NaLyg protein purified by prokaryotic expression killed some gram-negative bacterial pathogens by inducing cell wall destruction,including V.harveyi,Aeromonas hydrophila and Edwardsiella tarda.Moreover,the NaLyg protein killed two gram-positive bacteria,Bacillus subtilis and Staphylococcus aureus.Taken together,the experimental results suggested that the NaLyg protein of N.albiflora played an important role in fighting bacterial infections.展开更多
Nickel,an important transi-tion metal element,is one of the trace elements for hu-man body and has a crucial impact on life and health.Some evidences show the excess exposure to metal ions might be associated with neu...Nickel,an important transi-tion metal element,is one of the trace elements for hu-man body and has a crucial impact on life and health.Some evidences show the excess exposure to metal ions might be associated with neurological diseases.Herein,we applied Raman spectroscopy to study the Ni(II)ion effect on kinetics of amyloid fibrillation of hen egg white lysozyme(HEWL)in thermal and acidic conditions.Using the well-known Raman indicators for protein tertiary and secondary structures,we monitored and analyzed the concentration effect of Ni(II)ions on the unfolding of tertiary structures and the transformation of sec-ondary structures.The experimental evidence validates the accelerator role of the metal ion in the kinetics.Notably,the additional analysis of the amide I band profile,combined with thioflavin-T fluorescence assays,clearly indicates the inhibitory effect of Ni(II)ions on the formation of amyloid fibrils with organizedβ-sheets structures.Instead,a more significant promotion influence is affirmed on the assembly into other aggregates with disordered struc-tures.The present results provide rich information about the specific metal-mediated protein fibrillation.展开更多
In this study, we exhibited an amino acid (arginine and threonine) derivative Schiff base copper(II) complexes incorporating an azobenzene moiety as a photoresponsive site and conjugated it to egg white lysozyme, a we...In this study, we exhibited an amino acid (arginine and threonine) derivative Schiff base copper(II) complexes incorporating an azobenzene moiety as a photoresponsive site and conjugated it to egg white lysozyme, a well-known protein, to change ligand conformation under binding to lysozyme. Among several spectroscopic investigations, ESR clearly showed that the nitrogen atom of the amino acid residue of lysozyme was bound to the paramagnetic copper(II) ion of the complex, and UV light irradiation confirmed photoisomerization of the azobenzene moiety of the ligand to cis-form. The binding mode was considered by means of spectroscopic as well as computational methods, whereas complete crystallographic verification was still a preliminary stage.展开更多
Objective:Avidly phagocytosed hemozoin(malarial pigment) alters several functions of human monocytes and stimulates generation of several cytokines.Recently,we showed that phagocytosis of hemozoin by human monocytes i...Objective:Avidly phagocytosed hemozoin(malarial pigment) alters several functions of human monocytes and stimulates generation of several cytokines.Recently,we showed that phagocytosis of hemozoin by human monocytes increases expression and activity of matrix metalloproteinase-9,a proteolytic enzyme available in specific gelatinase granules,which contain several enzymes including lysozyme.Present work investigated active lysozyme release after phagocytosis of hemozoin and its dependence on production of tumor necrosis factor alpha. Methods:After phagocytosis of hemozoin,hemozoin-containing trophozoites or control meals(opsonized nonparasitized red blood cells and latex particles),monocyte supematants were monitored for 2 hours,in presence of blocking anti-human tumor necrosis factor alpha antibodies or recombinant human tumor necrosis factor alpha cytokine in selected experiments.Lysozyme release was evaluated by a specific spectrometric assay measuring lysozyme activity after coincubation of cell supematants with suspensions of Mycrococcus Lysodeikticus,while levels of soluble tumor necrosis factor alpha were analyzed by specific enzyme-linked immunodsorbent assay. Results:Levels of lysozyme activity and soluble tumor necrosis factor alpha protein were increased in hemozoin in-or trophozoites-laden monocytes supematants.Phagocytosis per se(control meals) also increased lysozyme release,but levels were significantly lower than those obtained after phagocytosis of hemozoin or trophozoites. Interestingly,all effects on lysozyme release observed after phagocytosis were abrogated by blocking anti-human tumor necrosis factor alpha antibodies,while they were mimicked by recombinant human tumor necrosis factor alpha cytokine.Conclusions:Present work shows that phagocytosis of hemozoin promotes monocyte degranulation and enhances active lysozyme release.The effect requires tumor necrosis factor alpha mediation.展开更多
The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters wer...The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters were optimized by using the respond surface methodology(RSM). The corrosion inhibition performance of co-immobilized lipase and lysozyme was evaluated by weight loss measurements and electrochemical measurements. The results revealed that the optimal co-immobilization method should be the sequential immobilization of lysozyme and then lipase. The inhibition efficiency was 86.10% under the optimal co-immobilized conditions. Electrochemical data showed that co-immobilized lysozyme and lipase was a mixed-type inhibitor and the corrosion inhibition efficiency was 81%.展开更多
The performance of the immobilized lysozyme and the native lysozyme on enhancing the excess sludge dewaterability was investigated.The results indicated that the specific resistance to filtration(SRF)decreased by 62.8...The performance of the immobilized lysozyme and the native lysozyme on enhancing the excess sludge dewaterability was investigated.The results indicated that the specific resistance to filtration(SRF)decreased by 62.8%for native lysozyme and 53.6%for immobilized lysozyme at the enzyme dosage of 9 mg/g(dry sludge).Correlation analysis was carried out to explore the role of different extracellular polymeric substance(EPS)fractions on excess sludge dewaterability.The results illustrated that the SRF negatively correlated with protein,polysaccharide from soluble EPS(S-EPS)and loosely bound EPS(LB-EPS)and positively correlated with that from tightly bound EPS(TB-EPS).Three-dimensional excitation emission matrix(3D-EEM)fluorescence analysis combined with the scanning electron microscope(SEM)images,revealed that sludge floc structure and microbial cells were destroyed by enzymatic treatment,and that the enzymatic hydrolysis could help to improve the transformation of hydrophilic groups from TB-EPS and the performance of the excess sludge dewatering process.The assessment of hydrolysis using the immobilized enzyme provided a new insight for the safe disposal of the sludge.展开更多
Soybean cyst nematode(SCN, Heterodera glycines(I.)) is one of the most important soil-borne pathogens for soybeans. In plant parasitic nematodes, including SCN, lysozyme plays important roles in the innate defense sys...Soybean cyst nematode(SCN, Heterodera glycines(I.)) is one of the most important soil-borne pathogens for soybeans. In plant parasitic nematodes, including SCN, lysozyme plays important roles in the innate defense system. In this study, two new lysozyme genes(Hg-lys1 and Hg-lys2) from SCN were cloned and characterized. The in situ hybridization analyses indicated that the transcripts of both Hg-lys1 and Hg-lys2 accumulated in the intestine of SCN. The q RT-PCR analyses showed that both Hg-lys1 and Hg-lys2 were upregulated after SCN second stage juveniles(J2 s) were exposed to the Grampositive bacteria Bacillus thuringiensis, Bacillus subtilis or Staphylococcus aureus. Knockdown of the identified lysozyme genes by in vitro RNA interference caused a significant decrease in the survival rate of SCN. All of the obtained results indicate that lysozyme is very important in the defense system and survival of SCN.展开更多
In order to improve the stability and corrosion inhibition performance of bioenzyme, lipase and lsozyme were co-immobilized on the mesoporous molecular sieve MCM-41 by the adsorption method. Then the immobilized enzym...In order to improve the stability and corrosion inhibition performance of bioenzyme, lipase and lsozyme were co-immobilized on the mesoporous molecular sieve MCM-41 by the adsorption method. Then the immobilized enzymes were combined with amino trimethylene phosphonic acid and polyaspartic acid to prevent corrosion caused by circulating cooling water. The weight-loss method and electrochemical techniques were used to evaluate the performance of composite inhibitors. The co-immobilized lysozyme and lipase achieved good inhibition effects. After they were combined with amino trimethylene phosphonic acid and polyaspartic acid, the corrosion inhibition properties were further improved. The inhibition efficiency was promoted to 94.4%. During the corrosion inhibition process, the immobilized enzymes played an important role. The addition of corrosion inhibitor could inhibit the anodic dissolution and cathodic hydrogen evolution process of carbon steel at the same time. The adsorption of co-immobilized lysozyme and lipase composite inhibitor on the steel surface was a joint action involving physical adsorption and chemical adsorption.展开更多
In the investigation of effect of KSCN on the partitioning of lysozyme in PEG2000/arnmonium sulfate aqueous two-phase system, it was found that the KSCN could alter the PH difference between the two phases, and thus a...In the investigation of effect of KSCN on the partitioning of lysozyme in PEG2000/arnmonium sulfate aqueous two-phase system, it was found that the KSCN could alter the PH difference between the two phases, and thus affect the partition of lysozyme. The relationship between partition coefficients of lysozyme and pH differences between two phases was discussed.展开更多
Aim To research therapeutical effect of marine lysozyme suppository on bacterial vaginitis caused by S. aureus and E. coll. Methods Lysozyme obtained from concha ostreae which were used to preparate marine lyso- zyme ...Aim To research therapeutical effect of marine lysozyme suppository on bacterial vaginitis caused by S. aureus and E. coll. Methods Lysozyme obtained from concha ostreae which were used to preparate marine lyso- zyme suppository. The identification and test of suppository was in line with the standards stated in Chinese pharma- coperia(2010 edition). After determined its quality control, we studied its therapeutical effect on bacterial vaginitis which caused by S. aureus and E. coli, by vaginitis model in rats infection of S. aureus bacteria and E. coli. Results The preparation technology of marine lysozyme suppository was simple, convenient and clinically effective. The marine lysozyme suppository was delivered by dose 0.5, 0.25, 0. 125 g ~ kg-1, the cure rates of S. aureus infec- tion were 80% , 50% and 30% , respectively, the cure rates of E. coli infection were 90% , 60% and 30% re- spectively, the cure rates of mixed infection were 92.9% , 82. 1% and 92.9% respectively. Marine lysozyme sup- pository had an outstanding therapeutical effect on bacterial vaginitis which caused by S. aureus and E. coll. Con- clusion The preparative process of marine lysozyme suppository was practicable, and it had a good therapeutic effect on bacterial vaginitis caused by S. aureus and E. coll.展开更多
The kinetic procedure of the unfolding of lysozyme induced by the reduction of disulfide was monitored by the time-resolved ESI-MS with a sheath liquid assistant electrospray interface. It was found that the reduction...The kinetic procedure of the unfolding of lysozyme induced by the reduction of disulfide was monitored by the time-resolved ESI-MS with a sheath liquid assistant electrospray interface. It was found that the reduction process for the eight disulfides had a less difference in the reaction time after denatured treatment. In addition, the alkylation of the reduced free thiols was much slower than the reduction procedure. An artifact peak produced by the CID fragmentation in the mass spectra was identified and the possible mechanism of the Hofmann elimination reaction was proposed.展开更多
Stabilization of proteins in delivery devices and design of appropriate protein carriers are major research issues due to the extreme sensitivity of proteins.Previously,negatively charged nanoparticles,consisting of p...Stabilization of proteins in delivery devices and design of appropriate protein carriers are major research issues due to the extreme sensitivity of proteins.Previously,negatively charged nanoparticles,consisting of poly(lactic-co-glycolic acid)(PLGA)and poly(styrene-co-4–styrene-sulfonate)(PSS),showed considerably high loading capacity for positively charged model protein lysozyme depending on the surface charge density of nanoparticles.展开更多
A protein may exist as an ensem-ble of di erent conformations in solution,which cannot be repre-sented by a single static structure.Molecular dy-namics(MD)simulation has become a useful tool for sampling protein confo...A protein may exist as an ensem-ble of di erent conformations in solution,which cannot be repre-sented by a single static structure.Molecular dy-namics(MD)simulation has become a useful tool for sampling protein conformations in solution,but force elds and water models are important issues.This work presents a case study of the bacteriophage T4 lysozyme(T4L).We have found that MD simulations using a classic AMBER99SB force eld and TIP4P water model cannot well describe hinge-bending domain motion of the wild-type T4L at the timescale of one microsecond.Other combinations,such as a residue-speci c force eld called RSFF2+and a dispersion-corrected water model TIP4P-D,are able to sample reasonable solution conformations of T4L,which are in good agreement with experimental data.This primary study may provide candidates of force elds and water models for further investigating conformational transition of T4L.展开更多
Understanding the inuence of nanoparticles on the formation of protein amyloid brillation is cru-cial to extend their application in related biological diagnosis and nanomedicines.In this work,Ra-man spectroscopy was ...Understanding the inuence of nanoparticles on the formation of protein amyloid brillation is cru-cial to extend their application in related biological diagnosis and nanomedicines.In this work,Ra-man spectroscopy was used to probe the amyloid brillation of hen egg-white lysozyme in the pres-ence of silver nanoparticles(Ag-NPs)at di erent concentrations,combined with atomic force mi-croscopy and thioavin T(ThT)uorescence assays.Four representative Raman indicators were utilized to monitor transformation of the protein tertiary and secondary structures at the molecular level:the Trp doublet bands at 1340 and 1360 cm^(-1),the disul de stretching vibrational peak at 507 cm^(-1),the N-Cα-C stretching vibration at 933 cm^(-1),and the amide I band.All experimental results con rmed the concentration-dependent inuence of AgNPs on the hen egg-white lysozyme amyloid brillation kinetics.In the presence of AgNPs at low concentration(17μg/mL),electrostatic interaction of the nanoparticles stabilizes disul de bonds,and protects the Trp residues from exposure to hydrophilic environment,thus leading to formation of amorphous aggregates rather than brils.However,with the action of AgNPs at high concentration(1700μg/mL),the native disul de bonds of hen egg-white lysozyme are broken to form Ag-S bonds owing to the competition of electrostatic interaction from a great deal of nanoparticles.As for providing functional surfaces for protein to interact with,AgNPs play a bridge role in direct transformation from-helices to organized-sheets.The present investigation sheds light on the controversial e ects of AgNPs on the kinetics of hen egg-white lysozyme amyloid brillation.展开更多
Background: Females can differentially deposit the immune factor lysozyme into eggs based on conditions of local breeding density and laying order.Materials: We collected 80 eggs from Great Cormorants(Phalacrocorax ca...Background: Females can differentially deposit the immune factor lysozyme into eggs based on conditions of local breeding density and laying order.Materials: We collected 80 eggs from Great Cormorants(Phalacrocorax carbo) and then analyzed whether the level of lysozymes in the eggs is related to breeding density and laying order.Results: Between clutches,the level of lysozyme in eggs is positively related to breeding density; while within a clutch,the level of lysozyme is positively related to the laying order.Conclusion: When parents breed under conditions of high density,they allocate more lysozymes to their offspring,a trait adaptive to the local environment.That the increase in the level of lysozymes is a function of the laying order seems a necessary condition to mitigate the hierarchy among siblings for improving the survival of the entire clutch.展开更多
It is well known that lysozyme, which catalyzes the hydrolysis of bacterial cell walls, is one of the important substances protecting the eye surface from bacterial infections. It was reported that the aminoglycoside ...It is well known that lysozyme, which catalyzes the hydrolysis of bacterial cell walls, is one of the important substances protecting the eye surface from bacterial infections. It was reported that the aminoglycoside antibiotics strongly inhibited the tear lysozyme activity. The lysozyme activity of tears which were added to different con- centrations of two aminoglycoside antibiotics and three other antibiotics was determined longitudinally. No influence of any antibiotics on tear lysozyme activity was found. Therefore it is unnecessary to worry about that the use of aminoglycosida antibic tics may weaken the defence function of the eye.展开更多
We present a method to characterize lysozyme pre-crystalline aggregates using a forward-light-scattering technique, which is highly sensitive to protein aggregates. The static light scattering properties at small angl...We present a method to characterize lysozyme pre-crystalline aggregates using a forward-light-scattering technique, which is highly sensitive to protein aggregates. The static light scattering properties at small angles of crystallizing lysozyme aggregates are discussed, and related to the crystallization conditions based on the concentration of added precipitant NaCl. Lysozyme solutions that started to crystallize because of precipitant exhibited profiles of forward light scattering that could be fitted by non-integer power laws, which indicated fractal aggregations of lysozyme had formed. Pre-crystalline solutions, in which lysozyme crystals later grew, had dense structural fractal clusters with fractal dimensions of D > 1.5. In contrast, solutions with aggregates in which crystals did not grow, had forward-light-scattering profiles that deviated from a power law or had lower power values.展开更多
Biomass charcoal powder (BCP) was used as a carrier matrix for immobilization of chicken egg white lysozyme. BCP was derived from plant biomass wastes such as dumped adzuki beans by pyrolysis without combustion under ...Biomass charcoal powder (BCP) was used as a carrier matrix for immobilization of chicken egg white lysozyme. BCP was derived from plant biomass wastes such as dumped adzuki beans by pyrolysis without combustion under nitrogen atmosphere and grinding with a jet mill. The amount of lysozyme immobilized on BCP of adzuki beans by adsorption was 11 μmol/g (0.16 g/g) at pH 7.0. The optimum pH values for free and immobilized lysozyme activities were 6.8 and 7.2, respectively. The optimum temperature for both free and immobilized lysozyme activities was 25℃. The half-life of immobilized lysozyme exhibited 1.8-fold compared to that of free lysozyme at 5℃. Moreover, the half life of immobilized lysozyme was 7 times greater than that of lysozyme at 90℃.展开更多
基金supported by the National Natural Science Foundation of China(No.32072969)the National Key R&D Program of China(No.2022YFD2401002)+1 种基金the Natural Science Foundation of Fujian Province(No.2022 J01325)the Open Research Fund Program of Fujian Provincial Key Laboratory of Marine Fishery Resources and Eco-Environment(No.Z822280).
文摘Lysozyme(EC3.2.1.17)plays an important role in the immune response;as a nonspecific immune factor,it can resist causative agents.Lysozyme can be divided into c-type and g-type in fish.In a previous study,through genome-wide association analysis,the g-type lysozyme gene,which is named NaLyg in yellow drum(Nibea albiflora),was found to be a key candidate gene for disease resistance in response to Vibrio harveyi infection.The cDNA of NaLyg was 1025 bp,including four exons and three introns,and its open reading frame(ORF)had a full-length of 582 bp,encoding 193 amino acids.NaLyg was found to be conserved during evolution through bioinformatic analyses.The NaLyg protein possessed a sugar binding domain and three catalytic sites,including Glu71,Asp84 and Asp101.Quantitative qRT-PCR results confirmed that NaLyg gene mRNA was visibly increased after V.harveyi infection.The NaLyg protein purified by prokaryotic expression killed some gram-negative bacterial pathogens by inducing cell wall destruction,including V.harveyi,Aeromonas hydrophila and Edwardsiella tarda.Moreover,the NaLyg protein killed two gram-positive bacteria,Bacillus subtilis and Staphylococcus aureus.Taken together,the experimental results suggested that the NaLyg protein of N.albiflora played an important role in fighting bacterial infections.
基金supported by the National Natural Science Foundation of China(No.22073088,No.22027801 and No.21873089).
文摘Nickel,an important transi-tion metal element,is one of the trace elements for hu-man body and has a crucial impact on life and health.Some evidences show the excess exposure to metal ions might be associated with neurological diseases.Herein,we applied Raman spectroscopy to study the Ni(II)ion effect on kinetics of amyloid fibrillation of hen egg white lysozyme(HEWL)in thermal and acidic conditions.Using the well-known Raman indicators for protein tertiary and secondary structures,we monitored and analyzed the concentration effect of Ni(II)ions on the unfolding of tertiary structures and the transformation of sec-ondary structures.The experimental evidence validates the accelerator role of the metal ion in the kinetics.Notably,the additional analysis of the amide I band profile,combined with thioflavin-T fluorescence assays,clearly indicates the inhibitory effect of Ni(II)ions on the formation of amyloid fibrils with organizedβ-sheets structures.Instead,a more significant promotion influence is affirmed on the assembly into other aggregates with disordered struc-tures.The present results provide rich information about the specific metal-mediated protein fibrillation.
文摘In this study, we exhibited an amino acid (arginine and threonine) derivative Schiff base copper(II) complexes incorporating an azobenzene moiety as a photoresponsive site and conjugated it to egg white lysozyme, a well-known protein, to change ligand conformation under binding to lysozyme. Among several spectroscopic investigations, ESR clearly showed that the nitrogen atom of the amino acid residue of lysozyme was bound to the paramagnetic copper(II) ion of the complex, and UV light irradiation confirmed photoisomerization of the azobenzene moiety of the ligand to cis-form. The binding mode was considered by means of spectroscopic as well as computational methods, whereas complete crystallographic verification was still a preliminary stage.
基金supported in the context of the Italian Malaria Network by grants from Compagnia di San Paolo-IMIthe University of Torino Intramural FundsRegione Piemonte,Ricerca Sanitaria Finalizzata 2007 to PA
文摘Objective:Avidly phagocytosed hemozoin(malarial pigment) alters several functions of human monocytes and stimulates generation of several cytokines.Recently,we showed that phagocytosis of hemozoin by human monocytes increases expression and activity of matrix metalloproteinase-9,a proteolytic enzyme available in specific gelatinase granules,which contain several enzymes including lysozyme.Present work investigated active lysozyme release after phagocytosis of hemozoin and its dependence on production of tumor necrosis factor alpha. Methods:After phagocytosis of hemozoin,hemozoin-containing trophozoites or control meals(opsonized nonparasitized red blood cells and latex particles),monocyte supematants were monitored for 2 hours,in presence of blocking anti-human tumor necrosis factor alpha antibodies or recombinant human tumor necrosis factor alpha cytokine in selected experiments.Lysozyme release was evaluated by a specific spectrometric assay measuring lysozyme activity after coincubation of cell supematants with suspensions of Mycrococcus Lysodeikticus,while levels of soluble tumor necrosis factor alpha were analyzed by specific enzyme-linked immunodsorbent assay. Results:Levels of lysozyme activity and soluble tumor necrosis factor alpha protein were increased in hemozoin in-or trophozoites-laden monocytes supematants.Phagocytosis per se(control meals) also increased lysozyme release,but levels were significantly lower than those obtained after phagocytosis of hemozoin or trophozoites. Interestingly,all effects on lysozyme release observed after phagocytosis were abrogated by blocking anti-human tumor necrosis factor alpha antibodies,while they were mimicked by recombinant human tumor necrosis factor alpha cytokine.Conclusions:Present work shows that phagocytosis of hemozoin promotes monocyte degranulation and enhances active lysozyme release.The effect requires tumor necrosis factor alpha mediation.
基金financially supported by the National Natural Science Foundation of China (project 21077133)the Natural Foundation of Shandong Province and the Top Talent Project of China University of Petroleum (16RC17040003)
文摘The corrosion inhibition performance of co-immobilized lysozyme and lipase was investigated in a recirculating cooling water system. Four methods were carried out in co-immobilization, and the operating parameters were optimized by using the respond surface methodology(RSM). The corrosion inhibition performance of co-immobilized lipase and lysozyme was evaluated by weight loss measurements and electrochemical measurements. The results revealed that the optimal co-immobilization method should be the sequential immobilization of lysozyme and then lipase. The inhibition efficiency was 86.10% under the optimal co-immobilized conditions. Electrochemical data showed that co-immobilized lysozyme and lipase was a mixed-type inhibitor and the corrosion inhibition efficiency was 81%.
基金“Textile Light”Application Basic Research in China(No.J201503)National Natural Science Foundation of China(No.U1660107)Graduate Innovation Fund of Donghua University,China(No.16D311304)
文摘The performance of the immobilized lysozyme and the native lysozyme on enhancing the excess sludge dewaterability was investigated.The results indicated that the specific resistance to filtration(SRF)decreased by 62.8%for native lysozyme and 53.6%for immobilized lysozyme at the enzyme dosage of 9 mg/g(dry sludge).Correlation analysis was carried out to explore the role of different extracellular polymeric substance(EPS)fractions on excess sludge dewaterability.The results illustrated that the SRF negatively correlated with protein,polysaccharide from soluble EPS(S-EPS)and loosely bound EPS(LB-EPS)and positively correlated with that from tightly bound EPS(TB-EPS).Three-dimensional excitation emission matrix(3D-EEM)fluorescence analysis combined with the scanning electron microscope(SEM)images,revealed that sludge floc structure and microbial cells were destroyed by enzymatic treatment,and that the enzymatic hydrolysis could help to improve the transformation of hydrophilic groups from TB-EPS and the performance of the excess sludge dewatering process.The assessment of hydrolysis using the immobilized enzyme provided a new insight for the safe disposal of the sludge.
基金supported the Central Public-Interest Scientific Institution Basal Research Fund, China (Y2019GH03)the Special Fund for Agro-Scientific Research in the Public Interest of China (210503114)SINOGRAIN Ⅱ (CHN-17/0019): Technological Innovation to Support Environmentally-Friendly Food Production and Food Safety Under a Changing Climate-Opportunities and Challenges for Norway-China Cooperation
文摘Soybean cyst nematode(SCN, Heterodera glycines(I.)) is one of the most important soil-borne pathogens for soybeans. In plant parasitic nematodes, including SCN, lysozyme plays important roles in the innate defense system. In this study, two new lysozyme genes(Hg-lys1 and Hg-lys2) from SCN were cloned and characterized. The in situ hybridization analyses indicated that the transcripts of both Hg-lys1 and Hg-lys2 accumulated in the intestine of SCN. The q RT-PCR analyses showed that both Hg-lys1 and Hg-lys2 were upregulated after SCN second stage juveniles(J2 s) were exposed to the Grampositive bacteria Bacillus thuringiensis, Bacillus subtilis or Staphylococcus aureus. Knockdown of the identified lysozyme genes by in vitro RNA interference caused a significant decrease in the survival rate of SCN. All of the obtained results indicate that lysozyme is very important in the defense system and survival of SCN.
基金financially supported by Shandong Natural Science Foundation (ZR201702140013)
文摘In order to improve the stability and corrosion inhibition performance of bioenzyme, lipase and lsozyme were co-immobilized on the mesoporous molecular sieve MCM-41 by the adsorption method. Then the immobilized enzymes were combined with amino trimethylene phosphonic acid and polyaspartic acid to prevent corrosion caused by circulating cooling water. The weight-loss method and electrochemical techniques were used to evaluate the performance of composite inhibitors. The co-immobilized lysozyme and lipase achieved good inhibition effects. After they were combined with amino trimethylene phosphonic acid and polyaspartic acid, the corrosion inhibition properties were further improved. The inhibition efficiency was promoted to 94.4%. During the corrosion inhibition process, the immobilized enzymes played an important role. The addition of corrosion inhibitor could inhibit the anodic dissolution and cathodic hydrogen evolution process of carbon steel at the same time. The adsorption of co-immobilized lysozyme and lipase composite inhibitor on the steel surface was a joint action involving physical adsorption and chemical adsorption.
基金This work is supported by State Key PrO-iect of Fundamental Research !(G1998061302) the National Natural Science Foundation
文摘In the investigation of effect of KSCN on the partitioning of lysozyme in PEG2000/arnmonium sulfate aqueous two-phase system, it was found that the KSCN could alter the PH difference between the two phases, and thus affect the partition of lysozyme. The relationship between partition coefficients of lysozyme and pH differences between two phases was discussed.
文摘Aim To research therapeutical effect of marine lysozyme suppository on bacterial vaginitis caused by S. aureus and E. coll. Methods Lysozyme obtained from concha ostreae which were used to preparate marine lyso- zyme suppository. The identification and test of suppository was in line with the standards stated in Chinese pharma- coperia(2010 edition). After determined its quality control, we studied its therapeutical effect on bacterial vaginitis which caused by S. aureus and E. coli, by vaginitis model in rats infection of S. aureus bacteria and E. coli. Results The preparation technology of marine lysozyme suppository was simple, convenient and clinically effective. The marine lysozyme suppository was delivered by dose 0.5, 0.25, 0. 125 g ~ kg-1, the cure rates of S. aureus infec- tion were 80% , 50% and 30% , respectively, the cure rates of E. coli infection were 90% , 60% and 30% re- spectively, the cure rates of mixed infection were 92.9% , 82. 1% and 92.9% respectively. Marine lysozyme sup- pository had an outstanding therapeutical effect on bacterial vaginitis which caused by S. aureus and E. coll. Con- clusion The preparative process of marine lysozyme suppository was practicable, and it had a good therapeutic effect on bacterial vaginitis caused by S. aureus and E. coll.
基金NFS of China(No.29927002)and Visiting Scholar Foundation of Key Lab. in University.
文摘The kinetic procedure of the unfolding of lysozyme induced by the reduction of disulfide was monitored by the time-resolved ESI-MS with a sheath liquid assistant electrospray interface. It was found that the reduction process for the eight disulfides had a less difference in the reaction time after denatured treatment. In addition, the alkylation of the reduced free thiols was much slower than the reduction procedure. An artifact peak produced by the CID fragmentation in the mass spectra was identified and the possible mechanism of the Hofmann elimination reaction was proposed.
文摘Stabilization of proteins in delivery devices and design of appropriate protein carriers are major research issues due to the extreme sensitivity of proteins.Previously,negatively charged nanoparticles,consisting of poly(lactic-co-glycolic acid)(PLGA)and poly(styrene-co-4–styrene-sulfonate)(PSS),showed considerably high loading capacity for positively charged model protein lysozyme depending on the surface charge density of nanoparticles.
基金This work was supported by the National Natu-ral Science Foundation of China(No.91953101 and No.21573205)the Strategic Priority Research Program of the Chinese Academy of Science(XDB37040202),the Hefei National Science Center Pilot Project Funds,and the New Concept Medical Research Fund of USTC.
文摘A protein may exist as an ensem-ble of di erent conformations in solution,which cannot be repre-sented by a single static structure.Molecular dy-namics(MD)simulation has become a useful tool for sampling protein conformations in solution,but force elds and water models are important issues.This work presents a case study of the bacteriophage T4 lysozyme(T4L).We have found that MD simulations using a classic AMBER99SB force eld and TIP4P water model cannot well describe hinge-bending domain motion of the wild-type T4L at the timescale of one microsecond.Other combinations,such as a residue-speci c force eld called RSFF2+and a dispersion-corrected water model TIP4P-D,are able to sample reasonable solution conformations of T4L,which are in good agreement with experimental data.This primary study may provide candidates of force elds and water models for further investigating conformational transition of T4L.
基金This work was supported by the National Natu-ral Science Foundation of China(No.22073088 and No.21873089).
文摘Understanding the inuence of nanoparticles on the formation of protein amyloid brillation is cru-cial to extend their application in related biological diagnosis and nanomedicines.In this work,Ra-man spectroscopy was used to probe the amyloid brillation of hen egg-white lysozyme in the pres-ence of silver nanoparticles(Ag-NPs)at di erent concentrations,combined with atomic force mi-croscopy and thioavin T(ThT)uorescence assays.Four representative Raman indicators were utilized to monitor transformation of the protein tertiary and secondary structures at the molecular level:the Trp doublet bands at 1340 and 1360 cm^(-1),the disul de stretching vibrational peak at 507 cm^(-1),the N-Cα-C stretching vibration at 933 cm^(-1),and the amide I band.All experimental results con rmed the concentration-dependent inuence of AgNPs on the hen egg-white lysozyme amyloid brillation kinetics.In the presence of AgNPs at low concentration(17μg/mL),electrostatic interaction of the nanoparticles stabilizes disul de bonds,and protects the Trp residues from exposure to hydrophilic environment,thus leading to formation of amorphous aggregates rather than brils.However,with the action of AgNPs at high concentration(1700μg/mL),the native disul de bonds of hen egg-white lysozyme are broken to form Ag-S bonds owing to the competition of electrostatic interaction from a great deal of nanoparticles.As for providing functional surfaces for protein to interact with,AgNPs play a bridge role in direct transformation from-helices to organized-sheets.The present investigation sheds light on the controversial e ects of AgNPs on the kinetics of hen egg-white lysozyme amyloid brillation.
基金financially supported by the State Forestry Administration Program (Grant Nos. Y31I351B01)the National Natural Science Foundation of China (Grant Nos. Y011331501)+1 种基金the National Science & Technology Pillar Program (Grant Nos. 2008BADB0B0303)National Basic Research Program of China (Grant Nos. 2010CB530301)
文摘Background: Females can differentially deposit the immune factor lysozyme into eggs based on conditions of local breeding density and laying order.Materials: We collected 80 eggs from Great Cormorants(Phalacrocorax carbo) and then analyzed whether the level of lysozymes in the eggs is related to breeding density and laying order.Results: Between clutches,the level of lysozyme in eggs is positively related to breeding density; while within a clutch,the level of lysozyme is positively related to the laying order.Conclusion: When parents breed under conditions of high density,they allocate more lysozymes to their offspring,a trait adaptive to the local environment.That the increase in the level of lysozymes is a function of the laying order seems a necessary condition to mitigate the hierarchy among siblings for improving the survival of the entire clutch.
文摘It is well known that lysozyme, which catalyzes the hydrolysis of bacterial cell walls, is one of the important substances protecting the eye surface from bacterial infections. It was reported that the aminoglycoside antibiotics strongly inhibited the tear lysozyme activity. The lysozyme activity of tears which were added to different con- centrations of two aminoglycoside antibiotics and three other antibiotics was determined longitudinally. No influence of any antibiotics on tear lysozyme activity was found. Therefore it is unnecessary to worry about that the use of aminoglycosida antibic tics may weaken the defence function of the eye.
文摘We present a method to characterize lysozyme pre-crystalline aggregates using a forward-light-scattering technique, which is highly sensitive to protein aggregates. The static light scattering properties at small angles of crystallizing lysozyme aggregates are discussed, and related to the crystallization conditions based on the concentration of added precipitant NaCl. Lysozyme solutions that started to crystallize because of precipitant exhibited profiles of forward light scattering that could be fitted by non-integer power laws, which indicated fractal aggregations of lysozyme had formed. Pre-crystalline solutions, in which lysozyme crystals later grew, had dense structural fractal clusters with fractal dimensions of D > 1.5. In contrast, solutions with aggregates in which crystals did not grow, had forward-light-scattering profiles that deviated from a power law or had lower power values.
文摘Biomass charcoal powder (BCP) was used as a carrier matrix for immobilization of chicken egg white lysozyme. BCP was derived from plant biomass wastes such as dumped adzuki beans by pyrolysis without combustion under nitrogen atmosphere and grinding with a jet mill. The amount of lysozyme immobilized on BCP of adzuki beans by adsorption was 11 μmol/g (0.16 g/g) at pH 7.0. The optimum pH values for free and immobilized lysozyme activities were 6.8 and 7.2, respectively. The optimum temperature for both free and immobilized lysozyme activities was 25℃. The half-life of immobilized lysozyme exhibited 1.8-fold compared to that of free lysozyme at 5℃. Moreover, the half life of immobilized lysozyme was 7 times greater than that of lysozyme at 90℃.