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
A strategy for the development of new vanadium-based drugs is the preparation of complexes that target proteins and bear molecules involved in the cellular metabolism as ligands,likeα-hydroxycarboxylic acids.Based on...A strategy for the development of new vanadium-based drugs is the preparation of complexes that target proteins and bear molecules involved in the cellular metabolism as ligands,likeα-hydroxycarboxylic acids.Based on these premises,this study explores the solution behaviour of the dioxidovanadium(V)complex of malic acid,Cs_(2)[V^(V)_(2)O_(4)(mal)_(2)]·2H_(2)O,and its interaction with the model protein lysozyme(HEWL)at room and at physiological temperature using 51V nuclear magnetic resonance(NMR),electrospray ionisation-mass spectrometry(ESI-MS)and X-ray crystallography.The results show the coexistence in aqueous solution of various molecular species containing two or ten V^(V)centres.In solution these species are formed regardless of the presence of HEWL,while at 37℃the formation of[V^(V)_(10)O_(28)]^(6−)(V_(10))is precluded when the protein is present.Crystallographic data reveal that,when protein crystals are incubated with the V compound at room temperature(25℃)and at pH 4.0,[VIVO]^(2+),[V^(V)_(2)O_(5)(mal)]^(2−),[V^(V)_(10)O_(26)]^(2−)and[V^(V)_(10)O_(28)]^(6−)are bound to the protein,while at 37℃,under the same conditions,only[VIVO]^(2+)interacts with HEWL.[V^(V)_(10)O_(28)]^(6−)can bind the protein both covalently(as[V^(V)_(10)O_(26)]^(2−)ion)and non-covalently.Whereas the transformation of[V^(V)_(2)O_(4)(mal)_(2)]^(2−)to[V^(V)_(2)O_(5)(mal)]^(2−)is expected on the basis of thermodynamic considerations,the formation of V10 and of the V_(10)-HEWL adduct is not easily predictable.Docking calculations confirm the experimental results and highlight the role of protein-protein interaction in the stabilization of the revealed adduct.This study demonstrates that vanadium compounds can undergo transformation in solution,giving rise to species that interact with proteins through several binding modes and stabilization mechanisms.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.
基金This research was funded by MIUR PRIN 2022-Cod.2022JMFC3X“Protein Metalation by Anticancer Metal-based Drugs”MIUR PRIN 2022-Cod.2022APCTNA“TRILLI-TRansforming metal Ions and Low-cost LIgands into next generation metallodrugs.
文摘A strategy for the development of new vanadium-based drugs is the preparation of complexes that target proteins and bear molecules involved in the cellular metabolism as ligands,likeα-hydroxycarboxylic acids.Based on these premises,this study explores the solution behaviour of the dioxidovanadium(V)complex of malic acid,Cs_(2)[V^(V)_(2)O_(4)(mal)_(2)]·2H_(2)O,and its interaction with the model protein lysozyme(HEWL)at room and at physiological temperature using 51V nuclear magnetic resonance(NMR),electrospray ionisation-mass spectrometry(ESI-MS)and X-ray crystallography.The results show the coexistence in aqueous solution of various molecular species containing two or ten V^(V)centres.In solution these species are formed regardless of the presence of HEWL,while at 37℃the formation of[V^(V)_(10)O_(28)]^(6−)(V_(10))is precluded when the protein is present.Crystallographic data reveal that,when protein crystals are incubated with the V compound at room temperature(25℃)and at pH 4.0,[VIVO]^(2+),[V^(V)_(2)O_(5)(mal)]^(2−),[V^(V)_(10)O_(26)]^(2−)and[V^(V)_(10)O_(28)]^(6−)are bound to the protein,while at 37℃,under the same conditions,only[VIVO]^(2+)interacts with HEWL.[V^(V)_(10)O_(28)]^(6−)can bind the protein both covalently(as[V^(V)_(10)O_(26)]^(2−)ion)and non-covalently.Whereas the transformation of[V^(V)_(2)O_(4)(mal)_(2)]^(2−)to[V^(V)_(2)O_(5)(mal)]^(2−)is expected on the basis of thermodynamic considerations,the formation of V10 and of the V_(10)-HEWL adduct is not easily predictable.Docking calculations confirm the experimental results and highlight the role of protein-protein interaction in the stabilization of the revealed adduct.This study demonstrates that vanadium compounds can undergo transformation in solution,giving rise to species that interact with proteins through several binding modes and stabilization mechanisms.
