真养产碱杆菌112R_4的二羧酸单酰胺酰胺水解酶  

A Dicarboxylate Monoamide Amidohydrolase (Half-Amidase) from Alcaligenes eutrophus 112R_4

作　　者：张英姿[1] 王宇[1] 余志华[1] 刘阳剑[1] 王绛[1] 丁久元[1] 

机构地区：[1]中国科学院微生物研究所,北京100080

出　　处：《微生物学报》2003年第1期87-93,共7页Acta Microbiologica Sinica

摘　　要：在一株具有环酰亚胺转化活性的真养产碱杆菌 1 1 2R4 中发现了一种特异性的二羧酸单酰胺酰胺水解酶 (半酰胺酶 ) ,它催化环酰亚胺代谢的第二步反应 ,将二羧酸单酰胺水解为二羧酸和氨。该酶的底物仅限于此代谢途径的第一个酶———酰亚胺酶的产物二羧酸单酰胺 ,而对其它的酰胺类化合物没有明显水解活性。真养产碱杆菌 1 1 2R4 中的半酰胺酶和酰亚胺酶在表达上具有相关性 ,环酰亚胺 (如琥珀酰亚胺 )和二羧酸单酰胺 (如琥珀酰胺酸 )对它们有正调控作用 ,游离氨离子显示出负调控作用 ,琥珀酸则在酶合成和活性两方面均表现出影响作用。对重组大肠杆菌中表达的半酰胺酶粗酶的部分性质进行了研究。钴离子对半酰胺酶的活性表现出促进作用 ,比活力提高到 3.37倍 ,表明半酰胺酶可能是一种金属结合酶。A dicarboxylate monoamide amidohydrolase (half-amidase) was identified from a cyclic-imide-metabolizing microorganism, Alcaligenes eutrophus 112R 4. The enzyme catalyzed the hydrolysis of monoamidated dicarboxylates, which were the hydrolyzing products of cyclic imides by imidase, to dicarboxylates and ammonia. The enzyme showed high catalytic activity to succinamic acid, but no obvious activity to aliphatic amides, amino acid amides, N-carbamoyl amino acids and urea was observed. The productions of half-amidase and imidase were correlative in Alcaligenes eutrophus 112R 4, in that succinimide and succinamic acid enhanced the expressions of these two enzymes simultaneously, while free ammonia repressed their expressions. Succinate showed regulation effects on either synthesis or activities of half-amidase and imidase. The characteristics of half-amidase were investigated by using the crude extract of recombined E. coli cell. The fact that cobalt ion stimulated the activity of half-amidase by a coefficient of 3.37, implied that half-amidase was probably a metal-binding enzyme.

关 键 词：真养产碱杆菌112R4 二羧酸单酰胺酰胺水解酶 半酰胺酶 环酰亚胺代谢 

分 类 号：Q936[生物学—微生物学] TQ460.38[化学工程—制药化工]