The hydrogenase reaction in Hydrogenobacter thermophilus strain TK-6, an obligately autotrophic, thermophilic, aerobic hydrogen-oxidizing bacterium, was studied in the membrane fraction, methionaquinone-depleted membrane, and purified membrane-bound hydrogenase. Both b and c type cytochromes were involved in the hydrogen oxidation. Methionaquinone mediated an electron transport between membrane-bound hydrogenase and cytochrome b560. Methionaquinone was reduced directly by purified hydrogenase. From these results, we conclude that methionaquinone is a direct natural electron acceptor for the membrane-bound hydrogenase in the strain.
(1975). Crystallization of 2-Ketogluconate Reductase from Gluconobacter liquefaciens. Agricultural and Biological Chemistry: Vol. 39, No. 11, pp. 2263-2264.
5-Ketogluconate reductase (5KGR) from the cell free extract of Gluconobacter liquefaciens (IFO 12388) was partially purified about 120-fold by a procedure employing ammonium sulfate fractionation, and DEAE-cellulose-, hydroxylapatite- and DEAE-Sephadex A-50-column chromatographies. NADP was specifically required for the oxidative reaction of gluconic acid. The optimum pH for the oxidation of gluconic acid (GA) to 5-ketogluconic acid (5KGA) by the enzyme was 10.0 and for the reduction of 5KGA was 7.5. The optimum temperature of the enzyme was 50°C for both reactions of oxidation and reduction. The enzyme was considerably unstable and lost all of its activity within 3 days. The enzyme activity was strongly inhibited with p-chloromercuribenzoate and mercury ion, but remarkably stimulated by EDTA (1 × 10−3m). Apparent Km values were 1.8 × 10−2m for GA, 0.9 × 10−3m for 5KGA, 1.6 × 10−5 m for NADP, and 1.1 × 10−5 m for NADPH2.
Journal Article Effect of Extracellular pH on the Respiratory Chain and Energetics of Gluconobacter suboxydans Get access Kazunobu Matsushita, Kazunobu Matsushita Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar You-ichiro Nagatani, You-ichiro Nagatani Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Emiko Shinagawa, Emiko Shinagawa Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Osao Adachi, Osao Adachi Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Minoru Ameyama Minoru Ameyama Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Agricultural and Biological Chemistry, Volume 53, Issue 11, 1 November 1989, Pages 2895–2902, https://doi.org/10.1080/00021369.1989.10869793 Published: 01 November 1989 Article history Received: 24 April 1989 Published: 01 November 1989
Journal Article Crystallization and Properties of Amine Dehydrogenase from Pseudomonas sp. Get access Emiko Shinagawa, Emiko Shinagawa Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Kazunobu Matsushita, Kazunobu Matsushita Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Koji Nakashima, Koji Nakashima Department of Laboratory Medicine, St. Luke’s College of Nursing, Akashi-cho, Chuo-ku, Tokyo 104, Japan Search for other works by this author on: Oxford Academic Google Scholar Osao Adachi, Osao Adachi Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Minoru Ameyama Minoru Ameyama Laboratory of Applied Microbiology, Department of Agricultural Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753, Japan Search for other works by this author on: Oxford Academic Google Scholar Agricultural and Biological Chemistry, Volume 52, Issue 9, 1 September 1988, Pages 2255–2263, https://doi.org/10.1080/00021369.1988.10869019 Published: 01 September 1988 Article history Received: 22 March 1988 Published: 01 September 1988
Mammalian choline dehydrogenase (EC 1.1.99.1) has been proved to be a quinoprotein in which pyrroloquinoline quinone (PQQ) is involved as the prosthetic group. The enzyme was purified from dog liver mitochondria by solubilizing the enzyme with Brij 58 and chromatographically separating it almost to homogeneity. The absorption spectrum of mammalian choline dehydrogenase indicated the presence of PQQ with a typical shoulder at 320 nm. Since PQQ was attached to the enzyme by a covalent linkage, the chromophore was isolated with an acid hydrolysate and the isolated chromophore gave rise the identical spectroscopic characteristics to that obtained from the amine oxidase of Aspergillus niger in which PQQ is covalently linked. The isolated chromophore potently activated apo-D-glucose dehydrogenase (EC 1.1.99.17) supporting the presence of PQQ in mammalian choline dehydrogenase.
