The Absorption Spectra of Methanol Dehydrogenase

MDH is usually coloured olive-green, the spectrum of the isolated enzyme having a characteristic absorption due to the prosthetic group at 

FIGURE 4. The absorption spectra of methanol dehydrogenase.The spectrum of the oxidised form is very difficult to determine and is often likely to be that of the cyanide or ammonia adducts. MDH is usually isolated in the reduced or half-reduced form (semiquinone). 

FIGURE 5. The absorption spectrum of MDH lacking calcium (broken line), isolated from mxaA mutant, and the effect of incorporation of calcium into the enzyme (solid line). Reproduced with permission from Goodwin et al. (1996), Biochemical Journal, 319, 839n842). the Biochemical Society. 

FIGURE 6. The reduction of oxidised Ba-MDH by endogenous substrate. MDH lacking any metal ion in its active site was produced from the mxaA mutant it was incubated with Ba + to produce Ba-MDH which was then oxidised with a small excess of Wursteris Blue which was then removed by rapid gel filtration and spectra recorded. Reproduced with permission from Goodwin and Anthony (1996), Biochemical Journal, 318, 673n679). the Biochemical Society. 

PYRROLO-QUINOLINE QUINONE (PQQ) THE PROSTHETIC GROUP OF METHANOL DEHYDROGENASE 

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