title: Immunocytochemical localization of the coenzyme F420-reducing hydrogenase in Methanosarcina barkeri Fusaro.
abstract: The cytological localization of the 8-hydroxy-5-deazaflavin (coenzyme F420)-reducing hydrogenase of Methanosarcina barkeri Fusaro was determined by immunoelectron microscopy, using a specific polyclonal rabbit antiserum raised against the homogeneous deazaflavin-dependent enzyme. In Western blot (immunoblot) experiments this antiserum reacted specifically with the native coenzyme F420-reducing hydrogenase, but did not cross-react with the coenzyme F420-nonreducing hydrogenase activity also detectable in crude extracts prepared from methanol-grown Methanosarcina cells. Immunogold labelling of ultrathin sections of anaerobically fixed methanol-grown cells from the exponential growth phase revealed that the coenzyme F420-reducing hydrogenase was predominantly located in the vicinity of the cytoplasmic membrane. From this result we concluded that the deazaflavin-dependent hydrogenase is associated with the cytoplasmic membrane in intact cells of M. barkeri during growth on methanol as the sole methanogenic substrate, and a possible role of this enzyme in the generation of the electrochemical proton gradient is discussed.
authors.affiliation: Gesellschaft für Biotechnologische Forschung mbH, Abteilung Mikrobiologie, Berlin, Federal Republic of Germany.
authors.forename: H
authors.initials: H
authors.lastname: Lünsdorf
authors.forename: M
authors.initials: M
authors.lastname: Niedrig
authors.forename: K
authors.initials: K
authors.lastname: Fiebig
mesh_terms: D015153:Blotting, Western; D002462:Cell Membrane / Q000201:enzymology; D003429:Cross Reactions; D019605:Euryarchaeota / Q000201:enzymology* / Q000648:ultrastructure; D007106:Immune Sera; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D010088:Oxidoreductases / Q000032:analysis* / Q000276:immunology / Q000378:metabolism
chemical_list: D007106:Immune Sera; D010088:Oxidoreductases; C033895:coenzyme F420 hydrogenase