EFFECT OF A WATER-MISCIBLE ORGANIC-SOLVENT ON THE KINETIC AND STRUCTURAL-PROPERTIES OF TRYPSIN

被引：39

作者：

GUINN, RM ^{[1
]}

BLANCH, HW ^{[1
]}

CLARK, DS ^{[1
]}

机构：

[1] UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720

来源：

ENZYME AND MICROBIAL TECHNOLOGY | 1991年 / 13卷 / 04期

基金：

美国国家科学基金会;

关键词：

TRYPSIN; ESTERASE; AMIDASE; STRUCTURE; KCAT; KM;

D O I：

10.1016/0141-0229(91)90151-Y

中图分类号：

Q81 [生物工程学（生物技术）]; Q93 [微生物学];

学科分类号：

071005 ; 0836 ; 090102 ; 100705 ;

摘要：

The effects of a water-miscible organic solvent (9:1 mix of DMF and DMSO) on the esterase and amidase kinetic parameters of trypsin have been investigated. The solvent selectively reduced the K(cat) for amidase activity relative to that for esterase activity. For both reaction types, K(m) increased sharply with increasing solvent concentration. Kinetic studies were complemented by fluorescent measurements of the enzyme's overall conformation and by EPR spectroscopy studies of the active-site microstructure. The decline in k(cat) for amidase activity began at solvent concentrations greater than 10%; this decrease correlated well with minor changes in the structure of the active site as indicated by EPR spectroscopy. In contrast, the esterase k(cat) showed no significant decrease throughout the solvent concentration range studied. The k(cat) values were based on the number of active sites as indicated by active site titration.

引用

页码：320 / 326

页数：7

共 23 条

[1] A SEARCH FOR PEPTIDE LIGASE - COSOLVENT-MEDIATED CONVERSION OF PROTEASES TO ESTERASES FOR IRREVERSIBLE SYNTHESIS OF PEPTIDES [J].