Purification and characterization of pectinesterase from Ficus awkeotsang.

Abstract

A pectinesterase (EC 3.1.1.11) isolated from red tepals of Ficus awkeotsang was purified to a single band of protein on SDS-PAGE by column chromatography on QAE-Sephadex A-25, Q-Sepharose, hydroxylapatite, and Sephacryl S-200. The molecular weight of the enzyme was 42, 000 by SDS-PAGE. The pI was 4.4. The purified enzyme activity was stimulated in the presence of low concentrations of metal ions, in the order of Ca2+>Mg2+>K+>Na+. The Km and Vmax for awkeotsang polygalacturonide were 2.94mg/ml, 66.67μmol/min/mg protein at pH 5.4 in the absence of metal ion, and 2.78mg/ml, 86.96μmol/min/mg protein at pH 7.5 in the presence of 50 mM KCI, respectively.