Hog Kidney and Intestine Aminoacylase-Catalyzed Acylation of L-Methionine in Aqueous Media

Abstract

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