Methanol oxidation under physiological conditions using methanol dehydrogenase and a factor isolated from Hyphomicrobium X

FEBS Letters

Dijkstra, Maarten¹  Duine, Johannes A.¹  Frank jzn, Johannes¹ 

[1] Department of Microbiology & Enzymology, Delft University of Technology, Julianalaan 67, 2628 BC Delft, The Netherlands

关键词: Methanol dehydrogenase;    Pyrroloquinoline quinone;    Cytochrome c L;    Methanol oxidation;    (Hyphomicrobium X);    PQQ;    pyrroloquinoline quinone;    Mops;    4-morpholinepropanesulphonic acid;    MDHred;    reduced methanol dehydrogenase;    MDHsem;    MDH in the semiquinone state;    THF;    tetrahydrofolate;    WB;    Wurster's blue (the free radical of N;    N;    N′;    N′-tetramethyl-p-phenylenediamine);   

DOI  :  10.1016/0014-5793(88)80898-6

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Anion-exchange chromatography of a cell-free extract from Hyphomicrobium X yielded a cytochrome c _H-containing methanol dehydrogenase (MDH) preparation only when all manipulations were carried out under anaerobic conditions. The properties of MDH in this preparation were unusual since significant activity could be detected in the absence of an artificial activator (NH⁺ ₄-salts) and the absorption spectrum was clearly different from that of MDH isolated in the usual way (aerobically). After gel filtration, the activator independency was lost, but reappeared when the front fractions (containing activator-dependent MDH) were combined with the low molecular mass fractions. Although the compound in these fractions (factor X) could replace the artificial activator in an assay at pH 9.0, it is clearly not an NH⁺ ₄-salt. In addition, it could not be replaced by coenzyme A, tetrahydrofolate, reduced glutathione, ubiquinone Q-9 or a number of divalent metal ions. Inactivation of factor X occurred in the presence of oxygen and cytochrome c. Using ferricytochrome c _L and MDH at pH 7.0, it was shown that factor X stimulates the methanol oxidation rate under this physiological condition.

【 授权许可】

Unknown