Lee Y H, Chang T S, Liu H J, Chu W S
Food Industry Research and Development Institute, Hsinchu, Taiwan 300, Republic of China.
Biotechnol Appl Biochem. 1998 Oct;28(2):113-8.
A glutaryl-7-aminocephalosporanic acid (GL-7-ACA) acylase was purified 58-fold from Pseudomonas nitroreducens in a two-step procedure involving osmotic shock and carboxymethyl-Sepharose chromatography with a yield of 26%. The molecular mass of the native enzyme was 58 kDa. SDS/PAGE revealed that it consisted of two non-identical subunits with molecular masses of 35 and 21 kDa. The isoelectric point of the purified enzyme was 5.3. The enzyme had an optimal pH of 5.5 and an optimal temperature of 43 degrees C. The purified enzyme exhibited not only GL-7-ACA acylase activity but also gamma-glutamyltranspeptidase activity. The Km values of the enzyme for GL-7-ACA and L-gamma-glutamyl p-nitroanilide were 10.41 mM and 5.92 microM respectively.
通过包括渗透休克和羧甲基琼脂糖凝胶层析的两步法从还原硝基假单胞菌中纯化出戊二酰 -7-氨基头孢烷酸（GL-7-ACA）酰化酶，纯化了58倍，产率为26%。天然酶的分子量为58 kDa。SDS/PAGE显示它由两个分子量分别为35 kDa和21 kDa的不同亚基组成。纯化酶的等电点为5.3。该酶的最适pH为5.5，最适温度为43℃。纯化酶不仅表现出GL-7-ACA酰化酶活性，还表现出γ-谷氨酰转肽酶活性。该酶对GL-7-ACA和L-γ-谷氨酰对硝基苯胺的Km值分别为10.41 mM和5.92 μM。
