Smigán P, Majerník A, Polák P, Hapala I, Greksák M
Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji.
FEBS Lett. 1995 Sep 4;371(2):119-22. doi: 10.1016/0014-5793(95)00866-8.
Two ATPases with different apparent molecular masses of approx. 500 kDa and 400 kDa were identified in the EDTA extract of the cell membranes of Methanobacterium thermoautotrophicum. Western blotting with polyclonal antiserum reactive with beta-subunit of mitochondrial ATPase from rat liver and yeast was used for further analysis of these ATPases. A strong crossreactivity with a single protein band with an apparent molecular weight of about 53 kDa (similar to beta-subunit of F-type ATPase from other sources) was found in protein extracts of whole cells of Methanobacterium thermoautotrophicum strains delta H and Marburg, as well as of Methanospirillum hungatei. This indicates the presence of F-type ATPase in methanogens. ATP synthesis driven by membrane potential which was generated by artificially-imposed delta pH in the presence of protonophorous uncoupler and sodium ions was stimulated by bafilomycin A1, an inhibitor of V- and A-type ATPases, as well as by harmaline, an inhibitor of Na+/H+ antiporter. These results indicate that cells of Methanobacterium thermoautotrophicum strain delta H contain the F-type ATP synthase which is Na(+)-translocating in addition to V- or A-type ATP synthase which is H(+)-translocating.
在嗜热自养甲烷杆菌细胞膜的EDTA提取物中鉴定出了两种表观分子量不同的ATP酶，分别约为500 kDa和400 kDa。使用与大鼠肝脏和酵母线粒体ATP酶β亚基反应的多克隆抗血清进行蛋白质免疫印迹，以进一步分析这些ATP酶。在嗜热自养甲烷杆菌δH菌株和马尔堡菌株以及亨氏甲烷螺菌的全细胞蛋白质提取物中，发现与一条表观分子量约为53 kDa的单一蛋白条带（类似于其他来源的F型ATP酶β亚基）有强烈的交叉反应。这表明产甲烷菌中存在F型ATP酶。在存在质子载体解偶联剂和钠离子的情况下，由人工施加的ΔpH产生的膜电位驱动的ATP合成受到V型和A型ATP酶抑制剂巴弗洛霉素A1以及Na+/H+反向转运蛋白抑制剂哈尔明碱的刺激。这些结果表明，嗜热自养甲烷杆菌δH菌株的细胞除了含有H+转运的V型或A型ATP合酶外，还含有Na+转运的F型ATP合酶。
