Purification and characterization of a polygalacturonase from the xylophagous insect Oncideres albomarginata chamela (Coleoptera: Cerambycidae)

Abstract

In this work we purified a polygalacturonase enzyme from the midgut of larvae of the xylophagous insect Oncideres albomarginata chamela . The polygalacturonase showed high enzymatic activity (390.7 U/mg) in the crude extract and was purified to apparent homogeneity by means of cation exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The molecular mass of the polygalacturonase was estimated to be 37 kDa by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme had an optimum pH of 6.0 and an optimum temperature of 50°C. According to the kinetic studies on polygalacturonic acid, the polygalacturonase showed a Km of 3.18 mg/ml and Vmax of 716.15 U/mg. The enzymatic properties of the purified enzyme correspond to those reported for highly active commercially produced enzymes, highlighting the potential of this insect enzyme to be used in industrial applications.