title: Novel H2-oxidizing [NiFeSe]hydrogenase from Desulfovibrio vulgaris Miyazaki F.
abstract: [NiFeSe]hydrogenases are promising biocatalysts in H2-based technology due to their high catalytic activity and O2-stability. Here, we report purification and characterization of a new membrane-associated [NiFeSe]hydrogenase from Desulfovibrio vulgaris Miyazaki F ([NiFeSe]DvMF). The [NiFeSe]DvMF was composed of two subunits, corresponding to a large subunit of 58.3 kDa and a small subunit of 29.3 kDa determined by SDS-PAGE. Unlike conventional [NiFeSe]hydrogenases having catalytic bias toward H2-production, the [NiFeSe]DvMF showed 11-fold higher specific activity of H2-oxidation (2444 U/mg) than that of H2-production (217 U/mg). At the optimal reaction temperature of the enzyme (65°C), the specific activity of H2-oxidation could reach up to 21,553 U/mg. Amperometric assays of the [NiFeSe]DvMF clearly indicated that the enzyme had a remarkable O2-stability. According to the amino acid sequence alignment, the conserved cysteine residue at position 281 in medial cluster of other [NiFeSe]hydrogenases was specifically replaced by a serine residue (Ser281) in the [NiFeSe]DvMF. These results indicate that the [NiFeSe]DvMF can play as a new H2-oxidizing and O2-stable biocatalyst, along with providing helpful insights into the structure-function relationship of [NiFeSe]hydrogenases.
authors.affiliation: International Institute for Carbon-Neutral Energy Research, Kyushu University, Nishi-ku, Fukuoka, Japan.
authors.forename: Kyoshiro
authors.initials: K
authors.lastname: Nonaka
authors.forename: Nga T
authors.initials: NT
authors.lastname: Nguyen
authors.forename: Ki-Seok
authors.initials: KS
authors.lastname: Yoon
authors.forename: Seiji
authors.initials: S
authors.lastname: Ogo
mesh_terms: D000595:Amino Acid Sequence; D055162:Biocatalysis; D016969:Desulfovibrio vulgaris / Q000201:enzymology* / Q000235:genetics; D006864:Hydrogenase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D016415:Sequence Alignment
chemical_list: C058560:nickel-iron-selenium hydrogenase; D006864:Hydrogenase