Romesser J A, Wolfe R S
J Bacteriol. 1982 Nov;152(2):840-7. doi: 10.1128/jb.152.2.840-847.1982.
The stimulation of carbon dioxide reduction to methane by addition of 2-(methylthio)ethanesulfonate (CH3-S-CoM) to cell extracts of Methanobacterium thermoautotrophicum was investigated. Similar stimulation of CO2 reduction by CH3-S-CoM was found for cell extracts of Methanobacterium bryantii and Methanospirillum hungatei. The CH3-S-CoM requirement could be met by the methanogenic precursors formaldehyde, serine, or pyruvate, or by 2-(ethylthio)ethanesulfonate (CH3CH2-S-CoM), but not by other coenzyme M derivatives. Efficient reduction of CO2 to CH4 was favored by low concentrations of CH3-S-CoM and high concentrations of CO2. Sulfhydryl compounds were identified as effective inhibitors of CO2 reduction. Both an allosteric model and a free-radical model for the mechanism of CO2 activation and reduction are discussed.
研究了向嗜热自养甲烷杆菌细胞提取物中添加2-（甲硫基）乙烷磺酸盐（CH3-S-CoM）对二氧化碳还原为甲烷的刺激作用。对于布氏甲烷杆菌和亨氏甲烷螺菌的细胞提取物，发现CH3-S-CoM对二氧化碳还原有类似的刺激作用。甲烷生成前体甲醛、丝氨酸或丙酮酸，或2-（乙硫基）乙烷磺酸盐（CH3CH2-S-CoM）可满足对CH3-S-CoM的需求，但其他辅酶M衍生物则不能。低浓度的CH3-S-CoM和高浓度的二氧化碳有利于将二氧化碳高效还原为甲烷。巯基化合物被确定为二氧化碳还原的有效抑制剂。讨论了二氧化碳活化和还原机制的变构模型和自由基模型。
