基因工程菌1016氨基酰化酶的酶学性质研究

Characterization of L-aminoacylase in Bioengineered Bacterium 1016

研究了基因工程菌 1 0 1 6所产的氨基酰化酶的酶学特性。该酶的拆分速率符合米氏方程 ,且在 0 .5mol/L的高底物浓度下 ,无底物抑制现象。 37℃时的米氏常数和最大反应速率分别为 0 .0 4 8mmol/L和 2 .1 78mmol/L·h。最适反应温度为 5 5℃。5 5℃时 ,Km为 0 .0 37mmol/L ,Vmax为 2 .5 5 8mmol/L·h。最适底物为乙酰蛋氨酸 ;热稳定性好。

The aminoacylase characteristics of bioengineered bacterium 1016 were investigated. The results showed that the reaction adhered to Michcelis-Menten equation and there was no substrate inhibition when substrate concentration was not higher than 0.5mol.L -. At 37℃, kinetic constants Km and Vm were 0.048mmol.L - and 2.178 mmol.L -h - respectively. At 55℃,Km was 0.037mmol.L - and Vm was 2.558mmol.L -h -. The optimal substrate and temperature for aminoacylase were N-AC-D,L-Met and 55℃ respectively. The aminoacylase activities could keep steady at higher temperatures.