title: Molybdenum-containing membrane-bound formate dehydrogenase isolated from Citrobacter sp. S-77 having high stability against oxygen, pH, and temperature.
abstract: Membrane-bound formate dehydrogenase (FDH) was purified to homogeneity from a facultative anaerobic bacterium Citrobacter sp. S-77. The FDH from Citrobacter sp. S-77 (FDHS77) was a monomer with molecular mass of approximately 150 kDa. On SDS-PAGE, the purified FDHS77 showed as three different protein bands with molecular mass of approximately 95, 87, and 32 kDa, respectively. Based on the N-terminal amino acid sequence analysis, the sequence alignments observed for the 87 kDa protein band were identical to that of the large subunit of 95 kDa, indicating that the purified FDHS77 consisted of two subunits; a 95 kDa large subunit and a 32 kDa small subunit. The purified FDHS77 in this purification did not contain a heme b subunit, but the FDHS77 showed significant activity for formate oxidation, determined by the Vmax of 30.4 U/mg using benzyl viologen as an electron acceptor. The EPR and ICP-MS spectra indicate that the FDHS77 is a molybdenum-containing enzyme, displaying a remarkable O2-stability along with thermostability and pH resistance. This is the first report of the purification and characterization of a FDH from Citrobacter species.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Nga T
authors.initials: NT
authors.lastname: Nguyen
authors.affiliation: International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yatabe
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan.
authors.forename: Ki-Seok
authors.initials: KS
authors.lastname: Yoon
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; International Institute for Carbon-Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan; Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Kawaguchi Center Building, 4-1-8 Honcho, Kawaguchi-shi, Saitama 332-0012, Japan. Electronic address: ogotcm@mail.cstm.kyushu-u.ac.jp.
authors.forename: Seiji
authors.initials: S
authors.lastname: Ogo
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D002954:Citrobacter / Q000737:chemistry* / Q000201:enzymology; D004795:Enzyme Stability; D005560:Formate Dehydrogenases / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D008982:Molybdenum / Q000737:chemistry* / Q000378:metabolism; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D021122:Protein Subunits / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D021122:Protein Subunits; D008982:Molybdenum; D005560:Formate Dehydrogenases; D010100:Oxygen
keywords: Citrobacter sp. S-77; Formate oxidation; Molybdenum-containing formate dehydrogenase; O(2)-stability; Thermostability; pH resistance