The preparation of the coenzyme of aspartic acid deaminase.

Since the advent of a novel technique of enzyme resolution of bacterial aspartic acid deaminase (Lichstein and Umbreit, 1947), this enzyme has been linked with biotin (Liclstein and Umbreit, 1947; Wright et al., 1949), with adenylic acid (Lichstein and Christman, 1948), and with a coenzyme present in yeast and liver extracts (Lichstein and Christman, 1949; Christman and Lichstein, 1950). These natural extracts were fractionated by paper partition chromatography to yield certain fractions devoid of free biotin, which stimulated the resolved aspartic acid dmins. Very strong acid hydrolysis of these fractions resulted in a material which would substitute for biotin in the growth of Saccharomyces cerevisiae. Further studies with these same coenzyme fractions (Lichstein, 1950) showed marked similarities of stimulations on the resolved systems known to be associated with biotin, namely aspartic acid, serine and threonine deaminases, and oxalacetic and succinic acid decarboxylases, regardless of the method of resolution employed. These results were indicative that the coenzyme was a biologically active form of biotin. This report is concerned with the chemical formation of this coenzyme by acid degradation of carbohydrates.