ISOLATION, PARTIAL PURIFICATION AND CHARACTERIZATION OF ALKALINE SERINE PROTEASE FROM SEEDS OF CUCUMIS MELO VAR AGRESTIS

B. Gayatri Devi, K.P.J.HemaLatha

Abstract: The present study shows the isolation, partial purification and characterization of alkaline protease from the seeds of Cucumis melo var agrestis, by a four step purification process. Its molecular weight was estimated to be 54KDa. Enzyme showed maximum activity at pH 9.0 and optimum temperature at40oCwith casein as substrate. The enzyme exhibited homogeneity as attested by a single protein band on both native PAGE and SDS PAGE. It is a monomeric enzyme and nonglycoprotein in nature. The km value of enzyme for casein as determined by double reciprocal plot was 2.5 mg/ml. It was strongly inhibited by PMSF but not by EDTA. The results indicate that the alkaline protease is a serine protease, similar to cucumisin from sarcocarp of melon fruit.

Keywords: Cucumis melo var agrestis, purification, characterization, monomeric, homogeneity, serine protease, cucumisin.

DOI: https://doi.org/10.15623/ijret.2014.0306016