KINETICS OF INACTIVATION OF 4-AMINOBUTYRATE AMINOTRANSFERASE BY 3-BROMOPYRUVATE

被引：4

作者：

BLESSINGER, KJ ^{[1
]}

TUNNICLIFF, G ^{[1
]}

机构：

[1] INDIANA UNIV,SCH MED,NEUROCHEM LAB,8600 UNIV BLVD,EVANSVILLE,IN 47712

来源：

BIOCHEMISTRY AND CELL BIOLOGY-BIOCHIMIE ET BIOLOGIE CELLULAIRE | 1992年 / 70卷 / 08期

关键词：

4-AMINOBUTYRATE; 4-AMINOBUTYRATE AMINOTRANSFERASE; INACTIVATION; 3-BROMOPYRUVATE; AFFINITY LABEL; PSEUDOMONAS-FLUORESCENS;

D O I：

10.1139/o92-109

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

3-Bromopyruvate inhibited 4-aminobutyrate aminotransferase (EC 2.6.1.19) from Pseudomonas fluorescens, apparently irreversibly. Kinetics of this inactivation were studied by continuously monitoring the enzyme reaction at 30-degrees-C in the presence of inhibitor. Irrespective of how high an inhibitor concentration was present, a maximum rate of inactivation was eventually achieved (5.9 x 10(-3) s-1), indicating the formation of a reversible inhibitor-enzyme complex before the final inactivation step. The dissociation constant of this complex was found to be 6.5 muM. This affinity labelling by 3-bromopyruvate suggests the presence of essential sulphydryl groups on the enzyme, since this compound is known to preferentially alkylate cysteinyl residues.

引用

页码：716 / 719

页数：4

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