Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2000.407.410RazzaqueM.A. SaudZ.A. AbsarN. KarimM.R. HashinagaF. 3200033Polyphenoloxidase (PPO), an important oxidative enzyme which played a vital role in the brewing of guava after infection with fruit-rot disease was purified from disease-affected guava. The method was accomplished by ion exchange chromatography of crude enzyme extract on DEAE-cellulose followed by CM-cellulose. The purified enzyme was found to be homogeneous as judged by polyacrylamide disc gel electrophoresis. Molecular weight of the enzyme was estimated to be 178 kDa and 180.5 kDa by gel filtration and SDS-PAGE respectively. The enzyme appeared to be a single polypeptide chain as revealed by SDS-PAGE either in presence or in absence of reducing agent. Optimum activity of the enzyme was at 48°C and pH around 8. Activity was destroyed completely in presence of EDTA, a metal chellator. Purified PPO showed an estimated km value of 4.4 mM for catechol as substrate.]]>Andrews, P.,196596595606Dong, Y.M., J.H. Xu and J.F. Guo,199032160164Fujita, S. and T. Tono,1988Solanum melongena).]]>46115123Ganesa, C., M.T. Fox and W.H. Flurkey,199298472479Gauillard, F. and F. Richard‐Forget,1997Pyrus communis L, cv Williams): Activation, purification and some properties.]]>744956Lourenco, E.J., J.D.S. Leao and V.A. Neves,1990Euterpe edulis).]]>52249259Lowry, O.H., N.J. Rosebrough, A.L. Farr and R.J. Randall,1951193265275Mahadevan, A. and R. Sridhar,19822nd Edn.,Pages: 316Pages: 316Mowlah, G. and S. Itoo,198229413417Moore, A.E. and B.A. Stone,1972Nicotiana glutinosa.]]>50791798Nema, A.G.,1991Xanthomonas campestrls pv. Betllcola.]]>44914Okey, E.N., E.J. Duncan, G. Sirju-charran and T.N. Sreenivasan,1997Phytophthora canker resistance in cacao: Role of peroxidase, polyphenoloxidase and phenylalanine ammonia-lyase.]]>145295299Owusu-Ansah, Y.J.,1989Zizania palustris).]]>37901904Ornstein, L.,1964121321349Raymond, J., N. Rakariyatham and J.L. Azanza,199334927931Razzaque, M.A.,19971997Soderhall, I.,1995393338Tsukamoto, T., M. Ishiguro and M. Funatsu,1986Musca domestica.]]>16573581Weber, K. and M. Osborn,196924444064412