HOG KIDNEY AND INTESTINE AMINOACYLASE-CATALYZED ACYLATION OF L-METHIONINE IN AQUEOUS-MEDIA

Synthesis of N-acyl-L-methionine derivatives was catalyzed by hog kidn ey and intestinal aminoacylase in aqueous media using various acyl don ors with acyl-chain lengths ranging from 1 to 6. Various reaction cond itions were tested by varying the pH of the buffer, the water-miscible organic solvent and Zn2+ concentrations. Using short chain fatty acid s, N-acyl-L-methionine derivatives were efficiently synthesized by bot h enzymes with a yield of about 20-30%, depending on the acid used. Th e optimal yield was achieved after a 17-h incubation of the reaction m ixture containing 0.02 M acyl sodium salt, 0.2 M L-methionine, 10 mu M ZnCl2 and 120 mU of aminoacylase in a 0.2M sodium phosphate buffer at pH 6.0 and 37 degrees C. The part potentially played by acylase in th e in vivo acylation of amino acids, and by extension that of proteins in general, is discussed.