Purification and Properties of Prolidase from Germinating Soybeans

Abstract

A prolidase was separated from germinating soybean(Glycine Max. AKIYOSHI) in a highly purified form by using ammonium sulfate precipitation, DEAE-cellulose chromatography, and Sephadex gel filtration. The enzyme liberated glycine from Gly-Pro and G1y-Sar. The specific activity of purified prolidase was 1.65 units/mg of protein for G1y-Pro. The enzyme did not possess Gly-Gly dipeptidase, Gly-Gly-Gly tripeptidase, aminopeptidase, carboxypeptidase, or endopeptidase activity. It had a pH optimum at 7.0 for Gly-Pro and exhibited maximum activity at 40° when incubated for 120 min. The values of s_{20, w} and D_{20, w} were 5.5 S and 6.6×10^-7 cm²/sec, respectively, and the molecular weight was calculated to be 78000 from these values.