Methane formation from acetyl phosphate in cell extracts of Methanosarcina barkeri Dependence of the reaction on coenzyme A

FEBS Letters

Thauer, R.K.¹  Fischer, R.¹ 

[1] Mikrobiologie, Fachbereich Biologie, Philipps-Universität, Karl-von-Frisch-Straße, D-3550 Marburg, FRG

关键词: Acetyl-CoA;    Acetyl phosphate;    Coenzyme A;    Methanogenesis;    Coenzyme M;    (Methanosarcina barkeri);   

DOI  :  10.1016/0014-5793(88)80009-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cell extracts (100 000 × g supernatant) of acetate grown Methanosarcina barkeri (strain MS) catalyzed the formation of methane from acetyl phosphate (apparent K _m ∼ 2 mM) with specific activities up to 50 nmol·min⁻¹·mg protein⁻¹, which is 25% of the specific rate of methane formation from acetate by intact cells. Methane formation from acetyl phosphate was strictly dependent on coenzyme A (CoA) (apparent K _m ∼ 0.1 mM), which was demonstrated with extracts pretreated with charcoal to remove endogenous CoA. The extracts contained high specific activities of acetate kinase (16 μmol·min⁻¹·mg protein⁻¹) and of phosphotransacetylase (26 μmol·min⁻¹·mg protein⁻¹). The findings indicate that methanogenesis from acetate proceeds via acetyl phosphate and acetyl-CoA as intermediates. Almost identical results were obtained with cell extracts of acetate grown M. barkeri (strain Fusaro).

【 授权许可】

Unknown