MICROBIAL-METABOLISM OF AMINO-ALCOHOLS - FORMATION OF COENZYME B12-DEPENDENT ETHANOLAMINE AMMONIA-LYASE AND ITS CONCERTED INDUCTION IN ESCHERICHIA-COLI
MICROBIAL-METABOLISM OF AMINO-ALCOHOLS - FORMATION OF COENZYME B12-DEPENDENT ETHANOLAMINE AMMONIA-LYASE AND ITS CONCERTED INDUCTION IN ESCHERICHIA-COLI
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DOI：
10.1042/bj1760751
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发表时间：
1978-01-01
影响因子：
4.1
通讯作者：
TURNER, JM
中科院分区：
文献类型：
--
作者：
BLACKWELL, CM;TURNER, JM
乙醇胺解氨酶形成的动力学研究。大肠杆菌表明辅酶B12（5“-脱氧腺苷钴胺素）与乙醇胺是共诱导剂。酶和免疫学试验未能显示分别由乙醇胺和钴胺素诱导的互补酶组分的形成。虽然对作为底物的乙醇胺具有特异性，但酶的形成是由某些类似物诱导的，2-氨基丙醇。氰基[57 Co]-钴胺素的实验表明，无论是辅酶B12，也不是一些更紧密结合coenzymically无活性的钴酰胺是必要的酶的体外稳定性。突变体E.获得了组成型形成乙醇胺氨裂解酶脱辅基酶的大肠杆菌，表明对于酶在体内的转录后稳定性而言，组装既不需要乙醇胺也不需要钴胺素。组成酶的形成受到分解代谢物的抑制，特别是葡萄糖。似乎乙醇胺和辅酶B12协同作用，诱导乙醇胺氨裂解酶的形成。术语协同感应是针对这种现象提出的。
Kinetic studies of ethanolamine ammonia-lyase formation by E. coli suggested that coenzyme B12 (5''-deoxyadenosylcobalamin), with ethanolamine, is a co-inducer. Enzymic and immunological tests failed to show the formation of complementary enzyme components induced separately by ethanolamine and cobalamin, respectively. Although specific for ethanolamine as the substrate, enzyme formation was induced by certain analogs, e.g., 2-aminopropan-1-ol. Experiments with cyano[57Co]-cobalamin suggested that neither coenzyme B12 nor some more tightly bound coenzymically inactive cobamide was necessary for enzyme stability in vitro. Mutants of E. coli were obtained which formed ethanolamine ammonia-lyase apoenzyme constitutively, showing that neither ethanolamine nor cobalamin was required for assembly for post-transcriptional stability of the enzyme in vivo. Constitutive enzyme formation was subject to catabolite repression, particularly by glucose. It appears likely that ethanolamine and coenzyme B12, acting in concert, induce ethanolamine ammonia-lyase formation. The term concerted induction is proposed for this phenomenon.