Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2001.98.102RahmanM. Mahbubar AbsarNurul 1200141The α-amylase from mango-pulp of Himsagar variety was purified by successive ion-exchange chromatography on DEAE-cellulose followed by CM-cellulose. The purified enzyme was found to be homogenous as judged by polyacrylamide gel electrophoresis. The molecular weight of a -amylase was estimated to be 54,500 by gel filtration and 55,200 by SDS-PAGE respectively. The enzyme showed the following characteristics : Neutral sugar content 4.8%, optimum pH 6.8, optimum temperature 37°C and Km value 0.33% against starch as substrate and absorption maximum at 279nm in aqueous solution. The activity of the enzyme was increased in the presence of metallic salts such as Ca2+, Mg2+ and Mn2+ while Fe2+, Zn2+ and Cu2+ inhibited the activities moderately. The effect of urea, guanidine-HCI and acetic acid on the activities of α-amylase were discussed.]]>Andrews, P.,196596595606Crueger, W. and A. Crueger,1990pp: 191-193pp: 191-193Davies, J.W. and E.C. Cocking196776285305DuBois, M., K.A. Gilles, J.K. Hamilton, P.A. Rebers and F. Smith,195628350356Gangwar, B.M. and R.S. Tripathi,197313230236Garcia, E. and F.M. Lajolo, 19885311811186Jian, J.L.,19883rd Edn.,Jayaraman, J.,1981pp: 53pp: 53Lowry, O.H., N.J. Rosebrough, A.L. Farr and R.J. Randall,1951193265275Mattoo, A.K. and V.V. Modi,196944308310Mattoo, K. and V.V. Modi,19691969pp: 111114Mao, W.W. and J.E. Kinsella, 19814614001403Ornstein, L.,1964121321349Pech, J.C. and A. Latche,19722314991502Pech, J.C., G. Bonneau and J. Fallot,197312299305Pesis, E., Y. Fuchs and G. Zauberman,1978103673676Rahman, M.M., N. Absar and M.A. Gofur,19972245246Robyt, T.F. and D.J. White,1990Takahashi, T., N. Inokuchi and M. Irie,1981Aspergillus saitoi.]]>89125134Tandon, D.K. and S.K. Kalra,198358449453Weber, K. and M. Osborn,196924444064412Witt, W. and J.J. Sauter,199641365372