The cleavage reactions of Ser-His and its N-terminal phosphorylated form - N-(O.O-diisopropyl) phosphoryl seryl-histidine (DIPP-Ser-His) were studied on DNA. It was found that the phosporylation of Ser-His caused the ...The cleavage reactions of Ser-His and its N-terminal phosphorylated form - N-(O.O-diisopropyl) phosphoryl seryl-histidine (DIPP-Ser-His) were studied on DNA. It was found that the phosporylation of Ser-His caused the lost of the cleavage activity on DNA. The result might give some clue on the regulation of the activity of protein by展开更多
Seryl-Histidine dipeptide(Ser-His) has been previously reported to be capable of cleaving DNAs and carboxyl esters,as well as proteins.The protein cleavage mechanism has not been addressed yet.As an initial step of pr...Seryl-Histidine dipeptide(Ser-His) has been previously reported to be capable of cleaving DNAs and carboxyl esters,as well as proteins.The protein cleavage mechanism has not been addressed yet.As an initial step of protein cleavage activity,the non-covalent binding affinity of Ser-His for proteins is a crucial prerequisite.In this work,we took cyclophilin A(CyPA) as a substrate protein,and evaluated the non-covalent interaction between CyPA and Ser-His using a combination of NMR spectroscopy and molecular modeling approach.Two independent Ser-His binding sites on CyPA were detected using 15N-1H heteronuclear single-quantum coherence(HSQC) spectra.Each binding site binds one Ser-His molecule.Dissociation constants,Kd1 and Kd2,were estimated to be 2.07 and 6.66 mmol/L,respectively,indicative of the weak non-covalent interaction between Ser-His and CyPA.Based on molecular modeling results,we suggest that both the α-amino and the side chain hydroxyl group of Ser-His are crucial for the non-covalent interaction between Ser-His and CyPA.This work sheds light on the molecular mechanism of Ser-His and its analogues cleaving proteins.展开更多
文摘The cleavage reactions of Ser-His and its N-terminal phosphorylated form - N-(O.O-diisopropyl) phosphoryl seryl-histidine (DIPP-Ser-His) were studied on DNA. It was found that the phosporylation of Ser-His caused the lost of the cleavage activity on DNA. The result might give some clue on the regulation of the activity of protein by
基金supported by grants from the National Natural Science Foundation of China ( 20732004, 30730026, 20805037)the Ministry of Science and Technology of China (2007CB914304)
文摘Seryl-Histidine dipeptide(Ser-His) has been previously reported to be capable of cleaving DNAs and carboxyl esters,as well as proteins.The protein cleavage mechanism has not been addressed yet.As an initial step of protein cleavage activity,the non-covalent binding affinity of Ser-His for proteins is a crucial prerequisite.In this work,we took cyclophilin A(CyPA) as a substrate protein,and evaluated the non-covalent interaction between CyPA and Ser-His using a combination of NMR spectroscopy and molecular modeling approach.Two independent Ser-His binding sites on CyPA were detected using 15N-1H heteronuclear single-quantum coherence(HSQC) spectra.Each binding site binds one Ser-His molecule.Dissociation constants,Kd1 and Kd2,were estimated to be 2.07 and 6.66 mmol/L,respectively,indicative of the weak non-covalent interaction between Ser-His and CyPA.Based on molecular modeling results,we suggest that both the α-amino and the side chain hydroxyl group of Ser-His are crucial for the non-covalent interaction between Ser-His and CyPA.This work sheds light on the molecular mechanism of Ser-His and its analogues cleaving proteins.
