A COMPARATIVE STUDY OF PROTEASE PRESENT IN THE LEAF AND LATEX OF HOLOSTEMMA ADA-KODIEN SCHULT.

Proteases, an important group of hydrolytic enzyme break the peptide bonds of proteins. Holostemma ada-kodien Schult. (Asclepiadaceae) is a medicinally important plant with therapeutic and pharmacological actions. The crude protease extracted from the leaves had an activity of 51.38 U/ml while that from the latex was with an activity of 290U/ml. Native PAGE and Zymogram analysis showed the presence of five different proteases in the leaf and two major proteases in the latex. Both the crude enzymes were subjected to purification by ammonium sulphate [(NH4)2 SO4] fractional precipitation followed by CM-Cellulose and DEAE-Cellulose column chromatography. The biochemical characterisation of major protease of the latex showed optimum temperature as 50oC while optimum pH was 7.0. The enzyme exhibited good thermal and pH stabilities. Effect of inhibitors, metal ions on activity, hydrolysis of protein substrates and effect of substrate concentration on reaction velocity were evaluated. This is the first report on the protease from H. ada-kodien.