Diethyl flavon-7-yl phosphate was synthesized by modified Atheron-Todd reaction. The result of ESI shows that the phosphated flavonoids possess stronger binding affinities toward proteins such as myoglobin, insulin an...Diethyl flavon-7-yl phosphate was synthesized by modified Atheron-Todd reaction. The result of ESI shows that the phosphated flavonoids possess stronger binding affinities toward proteins such as myoglobin, insulin and lysozyme and are easier to form the non-covalent complexes with them.展开更多
Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis o...Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis of AgNPs using green tea(GT)extract and two of its components,(-)-epigallocatechin gallate(EGCG)and(+)-catechin(Ct)as capping/stabilizing agents,is reported.The synthesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli,along with anticancer activity against HeLa cells.After administering nanoparticles to the body,they come in contact with proteins and results in the formation of a protein corona;hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme(HEWL)as a carrier protein.Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs.The binding constant(Kb)was found to be higher for EGCG-AgNPs((2.309±0.018)×104 M-1)than for GT-AgNPs and Ct-AgNPs towards HEWL.EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect,but GT-AgNPs had no such observable effects.Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL.The key findings of this research included the synthesis of AgNPs using GT extract and its constituent polyphenols,and showed significant antibacterial,anticancer and protein-binding properties.The-OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis,which might offer new opportunities having implications for nanomedicine and nanodiagnostics.展开更多
The refolding of denatured hen egg white lysozyme (HEWL) was examined by surfactants at a high final refolded HEWL concentration (1 mg/mL). Hexadecyltrimethylammonium bromide (CTAB) and sucrose fatty acid monoester (D...The refolding of denatured hen egg white lysozyme (HEWL) was examined by surfactants at a high final refolded HEWL concentration (1 mg/mL). Hexadecyltrimethylammonium bromide (CTAB) and sucrose fatty acid monoester (DK-SS) were used to dissolve denatured HEWL without denaturants such as guanidine hydrochloride (GuHCl) and urea. When denatured HEWL was perfectly dissolved in buffer solutions containing surfactants and dithiothreitol (DTT), the concentration of CTAB was about one-twentieth times less than that of DK-SS. The concentration of CTAB strongly affected the refolding yield, and the maximum refolding yield was obtained at 0.88 mM CTAB, which is around the critical micelle concentration of CTAB. The refolding yield was influenced by the molar ratio of oxidized glutathione (GSSG) to DTT, and the maximum refolding yield was obtained when [GSSG]/[DTT] was 1.5. The refolding yield was markedly dependent upon the solution pH of HEWL, and exhibited 80% at pH 5.2.展开更多
Animal lysozymes can selectively cleave a kind of glycosidic bond ofN-acetylglucosamine in the bacterial cell wall peptidoglycan. The hen egg-white lysozymeconsists of a single polypeptide chain containing 129 amino a...Animal lysozymes can selectively cleave a kind of glycosidic bond ofN-acetylglucosamine in the bacterial cell wall peptidoglycan. The hen egg-white lysozymeconsists of a single polypeptide chain containing 129 amino acid residues and fourdisulfide bonds. The three-dimensional structure of this enzyme was determined展开更多
文摘Diethyl flavon-7-yl phosphate was synthesized by modified Atheron-Todd reaction. The result of ESI shows that the phosphated flavonoids possess stronger binding affinities toward proteins such as myoglobin, insulin and lysozyme and are easier to form the non-covalent complexes with them.
基金the Science and Engineering Research Board(ECR File No.ECR/2016/000159 and CRG File No.CRG/2019/000852),Government of India,for funding this work。
文摘Green synthesis of silver nanoparticles(AgNPs)has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis of AgNPs using green tea(GT)extract and two of its components,(-)-epigallocatechin gallate(EGCG)and(+)-catechin(Ct)as capping/stabilizing agents,is reported.The synthesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli,along with anticancer activity against HeLa cells.After administering nanoparticles to the body,they come in contact with proteins and results in the formation of a protein corona;hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme(HEWL)as a carrier protein.Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs.The binding constant(Kb)was found to be higher for EGCG-AgNPs((2.309±0.018)×104 M-1)than for GT-AgNPs and Ct-AgNPs towards HEWL.EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect,but GT-AgNPs had no such observable effects.Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL.The key findings of this research included the synthesis of AgNPs using GT extract and its constituent polyphenols,and showed significant antibacterial,anticancer and protein-binding properties.The-OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis,which might offer new opportunities having implications for nanomedicine and nanodiagnostics.
文摘The refolding of denatured hen egg white lysozyme (HEWL) was examined by surfactants at a high final refolded HEWL concentration (1 mg/mL). Hexadecyltrimethylammonium bromide (CTAB) and sucrose fatty acid monoester (DK-SS) were used to dissolve denatured HEWL without denaturants such as guanidine hydrochloride (GuHCl) and urea. When denatured HEWL was perfectly dissolved in buffer solutions containing surfactants and dithiothreitol (DTT), the concentration of CTAB was about one-twentieth times less than that of DK-SS. The concentration of CTAB strongly affected the refolding yield, and the maximum refolding yield was obtained at 0.88 mM CTAB, which is around the critical micelle concentration of CTAB. The refolding yield was influenced by the molar ratio of oxidized glutathione (GSSG) to DTT, and the maximum refolding yield was obtained when [GSSG]/[DTT] was 1.5. The refolding yield was markedly dependent upon the solution pH of HEWL, and exhibited 80% at pH 5.2.
基金Project supported by the National High-Tech Program of China.
文摘Animal lysozymes can selectively cleave a kind of glycosidic bond ofN-acetylglucosamine in the bacterial cell wall peptidoglycan. The hen egg-white lysozymeconsists of a single polypeptide chain containing 129 amino acid residues and fourdisulfide bonds. The three-dimensional structure of this enzyme was determined
