从龟裂链霉菌中分离并鉴定一种具有严格底物特异性的新型L-谷氨酸氧化酶。

Isolation and characterization of a novel L-glutamate oxidase with strict substrate specificity from Streptomyces diastatochromogenes.

作者信息

Wang Lijuan, Peng Rihe, Tian Yongsheng, Liu Man, Yao Quanhong

机构信息

Shanghai Key Laboratory of Agricultural Genetics and Breeding, Biotechnology Research Institute of Shanghai Academy of Agricultural Sciences, 2901 Beidi Rd, Shanghai, China.

College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.

出版信息

Biotechnol Lett. 2017 Apr;39(4):523-528. doi: 10.1007/s10529-016-2269-y. Epub 2016 Dec 20.

DOI:10.1007/s10529-016-2269-y

PMID:27999974

Abstract

OBJECTIVES

To find an L-glutamate oxidase (LGox), to be used for the quantitative analysis of L-glutamic acid, an lgox gene encoding LGox from Streptomyces diastatochromogenes was isolated, cloned and characterized.

RESULTS

The gene had an ORF of 1974 bp encoding a protein of 657 amino acid residues. In comparison to the LGox precursor, the proteinase K-treated enzyme exhibited improved affinity to substrate and with a K of 0.15 mM and V of 62 μmol min mg. The 50% thermal inactivation temperature of the proteinase K treated enzyme was increased from 50 to 70 °C. The enzyme exhibited strict specificity for L-glutamate.

CONCLUSIONS

LGox treated by proteinase K exhibited strict specificity for L-glutamate, good thermostability and high substrate affinity.

摘要

目的

为了寻找一种用于L - 谷氨酸定量分析的L - 谷氨酸氧化酶（LGox），从龟裂链霉菌中分离、克隆并鉴定了编码LGox的lgox基因。

结果

该基因具有1974 bp的开放阅读框，编码一个由657个氨基酸残基组成的蛋白质。与LGox前体相比，经蛋白酶K处理的酶对底物的亲和力有所提高，其Km为0.15 mM，Vmax为62 μmol·min-1·mg-1。经蛋白酶K处理的酶的50%热失活温度从50℃提高到了70℃。该酶对L - 谷氨酸表现出严格的特异性。