Hydrogenase 3 but not hydrogenase 4 is major in hydrogen gas production by Escherichia coli formate hydrogenlyase at acidic pH and in the presence of external formate
Hydrogenase 3 but not hydrogenase 4 is major in hydrogen gas production by Escherichia coli formate hydrogenlyase at acidic pH and in the presence of external formate
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DOI：
10.1385/cbb:41:3:357
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发表时间：
2004-01-01
影响因子：
2.6
通讯作者：
Trchounian, A
中科院分区：
文献类型：
--
作者：
Mnatsakanyan, N;Bagramyan, K;Trchounian, A
当发酵大肠杆菌在葡萄糖上生长时能够产生甲酸和分子氢 (H-2)。 H-2 的形成由两种氢化酶 3 (Hyd-3) 和 4 (Hyd-4) 负责，它们与甲酸脱氢酶 H (Fdh-H) 一起构成不同的膜相关甲酸氢化酶。在弱碱性 pH 值（pH 7.5）下，H2 的产生依赖于 Hyd-4 和 F0F1-三磷酸腺苷 (ATPase)，而外部甲酸会增加 Hyd-3 的活性。在这项研究中，细胞在没有和有外部甲酸盐的情况下生长，研究了 H-2 产量对 pH 的依赖性。在这两种类型的细胞中，pH 值降低后，H2 产量都会增加。在酸性 pH 值（pH 5.5）下，该产物对 N,N'-二环己基碳二亚胺或渗透压休克变得不敏感，并且在很大程度上依赖于 Fdh-H 和 Hyd-3，但不依赖于 Hyd-4 和 F0F1-ATPase。结果表明，Hyd-3 在酸性 pH 条件下独立于 F0F1-ATP 酶在 H-2 产生中发挥着重要作用。
Fermenting Escherichia coli is able to produce formate and molecular hydrogen (H-2) when grown on glucose. H-2 formation is possessed by two hydrogenases, 3 (Hyd-3) and 4 (Hyd-4), those, in conjunction with formate dehydrogenase H (Fdh-H), constitute distinct membrane-associated formate hydrogenylases. At slightly alkaline pH (pH 7.5), the production of H2 was found to be dependent on Hyd-4 and the F0F1-adenosine triphosphate (ATPase), whereas external formate increased the activity of Hyd-3. In this study with cells grown without and with external formate, H-2 production dependent on pH was investigated. In both types of cells, H2 production was increased after lowering of pH. At acidic pH (pH 5.5), this production became insensitive either to N,N'-dicyclohexylcarbodiimide or to osmotic shock and it became largely dependent on Fdh-H and Hyd-3 but not Hyd-4 and the F0F1-ATPase. The results indicate that Hyd-3 has a major role in H-2 production at acidic pH independently on the F0F1-ATPase.