Isolation, characterization and potential application of deoxyribonuclease-free phosphatase from cassava leaves

Abstract

A deoxyribonuclease-free acid phosphatase from cassava leaves was prepared by ammonium sulfate precipitation, chromatofocusing and hydrophobic interaction chromatography with phenyl Sepharose. The enzyme was purified 36-fold and had a specific activity of 16 U/ mg protein. The enzyme preparation revealed a major phosphatase band of 77 kDa and three minor activity bands. The pH and temperature optima for enzyme activity were 5.2 and 60°C, respectively. The enzyme was inactivated by heating at 80°C for 15 minutes and could be stored at - 20°C for up to two months. The enzyme exhibited broad substrate specificity and had a Km, (p-nitrophenyl phosphate) value of 1.7 mM. It was strongly inhibited..