假单胞菌L-半胱氨酸合成酶的纯化和性质研究  

Purification and Properties of L-Cysteine Synthetase from Pseudomonas

作　　者：金永杰[1] 杨文博[1] 刘忠[1] 白钢[1] 余养盛[1] 

机构地区：[1]南开大学生命科学学院,天津300071

出　　处：《微生物学通报》2004年第6期68-72,共5页Microbiology China

摘　　要：假单胞菌TS 1 1 38的细胞浆液通过硫铵沉淀、SephadexG 75凝胶过滤、DEAE Cellulose5 2离子交换、SephadexG 1 0 0凝胶过滤等分离纯化手段分别将从L ATC合成L 半胱氨酸的两个酶———L ATC水解酶和L SCC水解酶纯化了 83 9和 90 3倍。SDS PAGE鉴定均为单一条带 ,两种酶的相对分子质量分别为 37 5和 42 8kD ;酶反应的最适温度均为 35℃ ,最适pH分别为 7 0和 8 0 ;酶的米氏常数分别为 0 67mmol L和 0 1 5mmol L ,最大反应速度分别为0 39× 1 0 3mmol L·min和 0 42× 1 0 3mmol L·min。The L-ATC hydrolase and L-SCC amidohydrolase which convert L-ATC to L-cysteine in Pseudomonas sp.TS-1138 are purified about 83.9 and 90.3 fold by salting-out method, Sephadex G-75 gel chromatography, DEAE-cellulose 52 ion exchange and Sephadex G-100 gel chromatography, etc. The purified enzyemes are both demonstrated by SDS-PAGE to be a homogeneous protein. Their molecular weight are about 37.5kD and42.8kDa respectively. The optimum reaction temperature are both 35℃, and the optimum pH are 7.0 and 8.0 respectively. The Km of the two enzymes are 0.67 mmol/L and 0.15 mmol/L, and the Vmax are 0.39×10 -3mmol/L·min and 0.42×10 -3mmol/L·min respectively.

关 键 词：L-ATC水解酶 L-SCC水解酶 酶纯化 酶性质 

分 类 号：TQ920[轻工技术与工程—发酵工程]