α,β-elimination reaction of O-acetylserine sulfhydrylase.: Is the pyridine ring required?

被引：16

作者：

Cook, PF ^{[1
]}

机构：

[1] Univ Oklahoma, Dept Chem & Biochem, Norman, OK 73019 USA

来源：

BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS | 2003年 / 1647卷 / 1-2期

关键词：

O-acetylserine sulfhydrylase; pyridoxal 5 '-phosphate; alpha; beta-elimination; site-directed mutagenesis;

D O I：

10.1016/S1570-9639(03)00052-9

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：

O-Acetylserine sulfhydrylase (OASS) catalyzes the elimination of acetate from O-acetyl-L-serine (OAS) followed by addition of bisulfide to give L-cysteine. Site-directed mutagenesis has been used to replace the active site serine, S272, which forms a hydrogen bond to N1 of pyridoxal 5-phosphate (PLP) with alanine and aspartate. Based on UV-visible spectral and steady-state kinetic studies, both mutant enzymes catalyze the elimination reaction with an efficiency equal to that of the wild-type enzyme. Data are consistent with an anti-E-2 reaction proposed for the elimination reaction. (C) 2003 Elsevier Science B.V. All rights reserved.

引用

页码：66 / 69

页数：4

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