Loginova N V, Shishkina V N, Trotsenko I U
Mikrobiologiia. 1976 Jan-Feb;45(1):41-7.
As was established by isotopic and ezymatic studies, there are some common features and certain differences in primary metabolic pathways of methanol, methylamine and trimethylamine in Hyphomicrobium vulgare ZV. Assimilation of the carbon of these compounds at the level of formaldehyde through the serine cycle is in common, formaldehyde being partly oxidized to CO2. The differences are manifested in the steps of conversion of C1-substrates prior to formaldehyde formation. The carbon of methanol enters the serine cycle immediately after the oxidation to formaldehyde. In the case of methyl-amine N-methylation of glutamate firstly occurs and gamma-glutamylmethylamide and N-methylglutamate are formed. Trimethylamine is oxidized by phenazine methosulphate-linked dehydrogenase to dimethylamine and then to methylamine by NADPH-dependent mono-oxygenase. Here two formaldehyde units are liberated which enter directly the serine cycle. The third formaldehyde unit is formed from methylamine via N-methyl-glutamate pathway.
正如同位素和酶学研究所证实的,普通生丝微菌ZV中甲醇、甲胺和三甲胺的初级代谢途径存在一些共同特征和某些差异。这些化合物的碳在甲醛水平通过丝氨酸循环进行同化是共同的,甲醛部分被氧化为二氧化碳。差异表现在甲醛形成之前C1底物的转化步骤中。甲醇的碳在氧化为甲醛后立即进入丝氨酸循环。对于甲胺,首先发生谷氨酸的N-甲基化,形成γ-谷氨酰甲基酰胺和N-甲基谷氨酸。三甲胺被吩嗪硫酸甲酯连接的脱氢酶氧化为二甲胺,然后被NADPH依赖的单加氧酶氧化为甲胺。在此过程中释放出两个甲醛单元,它们直接进入丝氨酸循环。第三个甲醛单元通过N-甲基谷氨酸途径由甲胺形成。