The comparative effects of biocytin and a yeast extract concentrate on aspartic acid deaminase.

Wright et al. (1949) announced the isolation in crystalline form of a naturally occurring complex of biotin from yeast, designated as biocytin. The possible metabolic role of biocytin in aspartic acid deaminase was studied by these investigators and the results showed that it was less active than an equivalent of biotin in the stimulation of this enzyme in aged bacterial suspensions. Inasmuch as reports from this laboratory (Lichstein and Umbreit, 1947; Lichstein and Christman, 1948) have been concerned with the role of biotin and adenylic acid in certain bacterial deaminases and, more recently (Lichstein and Christman, 1949), with the concentration from yeast extract of the coenzyme(s) of aspartic acid, serine, and threonine deaminases, it seemed desirable to test the activity of biocytin in parallel with biotin, adenylic acid, and this coenzyme fraction. Such a study has been possible because of the kindness of Dr. L. D. Wright, who made available to us some biocytin concentrate.