The presence of H+ and Na+‐translocating ATPases in Methanobacterium thermoautotrophicum and their possible function under alkaline conditions

FEBS Letters

Šmigáň, Peter¹  Majerník, Alan¹  Polák, Peter¹  Hapala, Ivan¹  Greksák, Miloslav¹ 

[1]Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, 900 28 Ivanka pri Dunaji, Slovak Republic

关键词: Methanogens;    ATP synthesis;    Na+/H+ antiporter;    Sodium ion-motive force;    TCS;    tetrachlorosalicylanilide;    Δμ0Na+;    electrochemical potential difference of Na+;    ΔpH and ΔpNa;    difference in concentrations of H+ and Na+;    respectively;   

DOI  :  10.1016/0014-5793(95)00866-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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 β-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 β-subunit of F-type ATPase from other sources) was found in protein extracts of whole cells of Methanobacterium thermoautotrophicum strains ΔH 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 ΔpH 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 ΔH contain the F-type ATP synthase which is Na⁺-translocating in addition to V- or A-type ATP synthase which is H⁺-translocating.

【 授权许可】

Unknown