title: Characterization and purification of the membrane-bound ATPase of the archaebacterium Methanosarcina barkeri.
abstract: Membrane-bound ATPase was found in membranes of the archaebacterium Methanosarcina barkeri. The ATPase activity required divalent cations, Mg2+ or Mn2+, and maximum activity was obtained at pH 5.2. The activity was specifically stimulated by HSO3- with a shift of optimal pH to 5.8, and N,N'-dicyclohexylcarbodiimide inhibited ATP hydrolysis. The enzyme could be solubilized from membranes by incubation in 1 mM Tris-maleate buffer (pH 6.9) containing 0.5 mM EDTA. The solubilized ATPase was purified by DEAE-Sepharose and Sephacryl S-300 chromatography. The molecular weight of the purified enzyme was estimated to be 420,000 by gel filtration through Sephacryl S-300. Polyacrylamide gel electrophoresis in sodium dodecyl sulfate revealed two classes of subunit, Mr 62,000 (alpha) and 49,000 (beta) associated in the molar ratio 1:1. These results suggest that the ATPase of M. barkeri is similar to the F0F1 type ATPase found in many eubacteria.
mesh_terms: D000251:Adenosine Triphosphatases / Q000302:isolation & purification* / Q000378:metabolism; D001105:Archaea / Q000201:enzymology*; D001419:Bacteria / Q000201:enzymology*; D001426:Bacterial Proteins / Q000302:isolation & purification* / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D008345:Manganese / Q000378:metabolism; D008565:Membrane Proteins / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight
chemical_list: D001426:Bacterial Proteins; D008565:Membrane Proteins; D008345:Manganese; D000251:Adenosine Triphosphatases; D008274:Magnesium