Parallel induction of D-arabitol and D-sorbitol dehydrogenases.

Scolnick, Edward M. (Harvard Medical School, Boston, Mass.) and Edmund C. C. Lin. Parallel induction of d-arabitol and d-sorbitol dehydrogenases. J. Bacteriol. 84:631-637. 1962.-Two inducible diphosphopyridine nucleotide-linked dehydrogenases are described in a bacterium isolated from the soil, Cellvibrio polyoltrophicus ATCC 14774. The first enzyme catalyzes the dehydrogenation of d-arabitol to d-xylulose and d-mannitol to d-fructose. The data suggest that in vivo this enzyme has the dual function of the utilization of both of these polyhydric alcohols. The second enzyme was found to act only on d-sorbitol, converting it to d-fructose. Evidence for its physiological function as a d-sorbitol dehydrogenase is also given. Both of these enzymes were found to be induced in parallel by any of the three polyhydric alcohols, d-arabitol, d-mannitol, and d-sorbitol. A common stereoconfiguration of the inducers for these enzymes is suggested. The parallel evolution of substrate specificity and inducer specificity is discussed with respect to the functional advantage that such a selective process might offer.