Studies on the Pectolytic Enzyme

Abstract

Pectinesterase was extracted from the pulp of tomato fruit (Lycopersicum esculentum var. Hikari) pericarp with 250 mM potassium phosphate buffer, pH 8.0, and purified about 60 folds by means of ammonium sulfate fractionation, chromatography on DEAE-cellulose and gel filtration on Sephadex G-100 column. The enzyme preparation thus obtained was confirmed to be homogeneous state both ultracentrifugationally and disk electrophoretically. The sedimentation coefficient of this enzyme was calculated to be 3.17 S.

Abstract

According to the result of amino acid analysis, cystine, methionine and histidine were not detectable. The Km value was 0.24% for citrus pectin. The enzymatic activity was increased in the presence of sodium chloride, which also broad the activity range. The optimum pH in the 100 mM sodium chloride was 8.0. There was a marked break in the Arrhenius plot at the temperature of 27°C and 31°C in the presence and absence of 100 mM sodium chloride, respectively. The effect of potassium β-indolacetate, gibberellin, 6-benzyladenine and N-dimethylamino succinamidic acid on this enzyme was not remarkable.