Studies on Amino Acids XIII–XIV.

Abstract

Screening experiments for ε-lysine acylase activity in microorganisms have been carried out. Namely, a number of bacteria, streptomyces, molds and yeasts were cultured on the medium containing ε-acyllysines, and ε-lysine acylase activity was estimated by liberated amino acid detected with paper chromatography of the cultural broth. As a result, the occurrence of ε-lysine acylase activity was observed in molds, especially in Aspergillus oryzae. In other organisms such as bacteria, streptomyces and yeasts, the activity was scarcely found under the conditions employed by the authors. By the same procedure employing acetylmethionine and ε-benzoyl-α-acetyllysine, acylase activity, that is, hydrolytic activity toward α-N-acyl amino acids, of the microorganisms was investigated. For the purpose of investigating the formation of ε-lysine activity in molds, especially, Aspergillus oryzae was studied, from which it was found to be an inducible enzyme system whose activity is undetectable without induction. The respective activities inducted with ε-benzoyl-l-, -d-, and -dl-lysines are capable of hydrolyzing both optical isomers of ε-benzoyllysine regardless of the optical nature of the inducers employed. Several enzymatic properties of this fungal ε-lysine acylase are also presented.