ABSTRACT
The purpose of this study was to investigate the in vitro effects of vegetable carbohydrates on the activity of microbial ß-glucuronidase (ßG) and the adsorption of the enzyme on carbohydrates. This study used pectin-protein complexes (PPCs) with molecular weights of 300 kDa isolated under conditions simulating a gastric environment from cabbage (HCl-PPCC and HCl+pepsin-PPCCP) and sweet pepper (PPCP and PPCPP). As a sample for comparison, microcrystalline cellulose was used. The activity of ßG from Escherichia coli was determined spectrophotometrically by the formation of the colored product from the breakdown of phenolphthalein-ß-D-glucuronide. Adsorption of ßG on biopolymers was studied by the retention of the enzyme on the membrane of a concentrator with a pore diameter of 300 kDa and by native PAGE. PPCCP and PPCC were established to increase the activity of ßG by 50 and 100%, respectively. Cellulose had a weak effect, whereas pepper PPC had no effect. All studied carbohydrates adsorb on ßG. The maximum ßG adsorption (15%) was observed with PPCC, whereas PPCCP absorbed 5% of the enzyme. Pepper PPCs and cellulose adsorbed up to 10% of the enzyme. There was a positive correlation between the increase of ßG activity in the presence of carbohydrates and enzyme adsorption on the polymers (r=0.80; P<0.01). The activity of the enzyme in the gel after electrophoresis of the PPCC+ßG mixture was inversely proportional to the concentration of PPCC in the mixture. A model explaining the effects of cabbage PPCs on the excretion of estrogens is proposed.