Signals from Reactions of Alcohols with Xanthine Oxidases and Dehydrogenases

Another key piece of information is the finding (Tanner and Bray, 1978b) that ethylene glycol is a substrate for xanthine oxidase, even though its turnover is 10 to 10 times slower than is that of xanthine. This raises the possibility, indeed the virtual certainty, that methanol is oxidized by the enzyme in the formation of the methanol Inhibited signal. 

Finally, Tanner and Bray (1978b) found that desulfo xanthine oxidase, though it does not oxidize xanthine at any significant rate, is nevertheless able to oxidize ethylene glycol at a rate apparently comparable to that at which the functional enzyme oxidizes this substrate. 

the three signals, methanol Inhibited, glycol Inhibited, and De- 

Formaldehyde is a good substrate for xanthine oxidase so that, here at least, the slow inactivating reaction (Booth, 1938) involved in development of the Inhibited signal (Pick et a/., 1971) must represent a side reaction, rather than a step on the main catalytic pathway. 

though the resting signals attracted much attention in the early days of EPR work on molybdenum-containing enzymes (Aleman et al, 1966) and study of them is illuminating in work on the enzymic mechanisms, their origin, in enzyme samples as isolated, appears both fortuitous and trivial. 

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