Purification and Properties of L-Cysteine Synthetase from Pseudomonas / 微生物学通报

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.