Jones P W, Turner J M
J Gen Microbiol. 1984 Feb;130(2):299-308. doi: 10.1099/00221287-130-2-299.
The activities of the enzymes ethanolamine ammonia-lyase, CoA-dependent and CoA-independent aldehyde dehydrogenases, and isocitrate lyase were assayed in Escherichia coli which had been grown on various sources of carbon and nitrogen. Induction of ethanolamine ammonia-lyase and of maximal levels of both aldehyde dehydrogenases required the concerted effects of ethanolamine and vitamin (or coenzyme) B12. Molecular exclusion chromatography revealed that, in the absence of one or both co-inducers, two repressible isoenzymes of CoA-dependent aldehyde dehydrogenase (mol. wts 900000 and 120000) were produced, these being replaced by two inducible isoenzymes (mol. wts 520000 and 370000) in the presence of both co-inducers. A similar inducible repressible series of isoenzymes was also observed for CoA-independent aldehyde dehydrogenase. No evidence was found for structural relationships between ethanolamine ammonia-lyase, CoA-dependent aldehyde dehydrogenase and CoA-independent aldehyde dehydrogenase, but mutant and physiological studies demonstrated that the induction of the first two enzymes is under common control. Evidence is presented for the operation of a previously unreported pathway of ethanolamine metabolism in E. coli.
在以各种碳源和氮源生长的大肠杆菌中，检测了乙醇胺氨裂解酶、辅酶A依赖性和非依赖性醛脱氢酶以及异柠檬酸裂解酶的活性。乙醇胺氨裂解酶以及两种醛脱氢酶达到最高水平的诱导需要乙醇胺和维生素（或辅酶）B12的协同作用。分子排阻色谱显示，在缺少一种或两种共诱导剂的情况下，会产生两种可阻遏的辅酶A依赖性醛脱氢酶同工酶（分子量分别为900000和120000），而在两种共诱导剂存在的情况下，它们会被两种诱导型同工酶（分子量分别为520000和370000）取代。对于辅酶A非依赖性醛脱氢酶，也观察到了类似的诱导型-可阻遏型同工酶系列。未发现乙醇胺氨裂解酶、辅酶A依赖性醛脱氢酶和辅酶A非依赖性醛脱氢酶之间存在结构关系，但突变体和生理学研究表明，前两种酶的诱导受共同控制。本文提供了证据，证明大肠杆菌中存在一条以前未报道的乙醇胺代谢途径。
