来自嗜热紫链霉菌OPC-520的一种编码耐热几丁质酶的基因在大肠杆菌中的表达。

Expression in Escherichia coli of a gene encoding a thermostable chitinase from Streptomyces thermoviolaceus OPC-520.

作者信息

Tsujibo H, Endo H, Miyamoto K, Inamori Y

机构信息

Osaka University of Pharmaceutical Sciences, Japan.

出版信息

Biosci Biotechnol Biochem. 1995 Jan;59(1):145-6. doi: 10.1271/bbb.59.145.

DOI:10.1271/bbb.59.145

PMID:7765967

Abstract

An expression plasmid for a thermostable chitinase gene from S. thermoviolaceus OPC-520 in E. coli was constructed. A cloned chitinase (Chi40) was purified from the periplasmic space of E. coli harboring the expression plasmid. The N-terminal sequence of Chi40 was 11 amino acids longer than that of chitinase from S. thermovilaceus OPC-520 (ST chitinase), however, a loss or addition of the amino acid residues did not affect the enzymatic properties. The mutations of Asp-145 and Glu-147 drastically decreased the specific activity of chitinase from the wild type, indicating that both amino acid residues are the best candidates for the essential catalytic residues of Chi40.

摘要

构建了用于在大肠杆菌中表达嗜热紫硫菌OPC-520的耐热几丁质酶基因的表达质粒。从携带该表达质粒的大肠杆菌周质空间中纯化出克隆的几丁质酶（Chi40）。Chi40的N端序列比嗜热紫硫菌OPC-520的几丁质酶（ST几丁质酶）长11个氨基酸，然而，氨基酸残基的缺失或添加并不影响酶的性质。Asp-145和Glu-147的突变显著降低了野生型几丁质酶的比活性，表明这两个氨基酸残基是Chi40必需催化残基的最佳候选者。