PURIFICATION AND CHARACTERIZATION OF DIGESTIVE AMYLASE FROM THE TASARSILKWORM, ANTHERAEA-MYLITTA (LEPIDOPTERA, SATURNIIDAE)

Digestive amylase was purified from larvae of Indian tasar silkworm. A ntheraea mylitta using ammonium sulphate precipitation, glycogen compl ex precipitation and gel filtration chromatography. Specific activity increased from 0.673 AU/mg in the crude digestive juice to 94.80 AU/mg in the final purified sample, Activity of the purified enzyme was 15- fold less than that of the digestive amylase of silkworm. Bombyx mori. The zymogram pattern of the purified amylase was similar to that of c rude digestive juice on 7.5% native PAGE. The purified enzyme exhibite d five bands on native PAGE, IEF of the purified enzyme also revealed five bands with pls of 6.5, 6.15, 5.9, 5.8 and 4.7, respectively. The purified enzyme is a single polypeptide chain with a M(r) of 58 kDa. T he amylase is most active at pH 9.5 and is a Ca2+ dependent endoenzyme which hydrolyses starch into maltose, maltotriose and maltotetrose an d hence behaves as an alpha-amylase (EC 3.2.1.1). The enzyme was unaff ected by the presence or absence of Cl-, with K-m for soluble starch o f 0.113%.