Electron transferase activity of diaphorase (NADH: acceptor oxidoreductase) from Bacillus stearothermophilus

Tomokazu Matsue, Hiroshi Yamada, Hsien Chang Chang, Isamu Uchida, Kazuhiko Nagata, Kosuke Tomita

研究成果: Article同行評審

39 引文 斯高帕斯(Scopus)


Electrochemical kinetic measurements were carried out for electron-transfer between NADH and the oxidized forms of mediators (ferrocenylmethanol (FMA), ferrocenyl-l-ethanol (FEA), N,N,N′,N′-tetramethylphenylenediamine (TMPD), Co(Phen)32+ and Fe(CN)64-) catalyzed by diaphorase (NADH:acceptor oxidoreductase, EC 1.6.99.-) purified from Bacillus stearothermophilus. Cyclic voltammograms for the mediators with excess NADH in the presence of diaphorase gave steady-state currents. The quantitative analysis of the dependence of the current on the mediator concentration yielded a Michaelis constant (Km) and molecular activity (k0), which are difficult to determine by the conventional spectrophotometric method. Small Km) and large k0 values were observed for the oxidized forms of FMA, FEA and TMPD compared to those for Co(Phen)33+ and Fe(CN)63-. It is suggested that the reaction pocket of the present diaphorase is hydrophobic. The present electrochemical procedure for the determination of the kinetic parameters is applicable widely to similar enzyme reactions.

頁(從 - 到)29-38
期刊Biochimica et Biophysica Acta (BBA)/Protein Structure and Molecular
出版狀態Published - 1990 三月 29

All Science Journal Classification (ASJC) codes

  • 生物物理學
  • 結構生物學
  • 生物化學
  • 分子生物學


深入研究「Electron transferase activity of diaphorase (NADH: acceptor oxidoreductase) from Bacillus stearothermophilus」主題。共同形成了獨特的指紋。