Interaction of microbial β-glucuronidase with vegetable pectins

J Agric Food Chem. 2011 Sep 28;59(18):9922-6. doi: 10.1021/jf202307r. Epub 2011 Sep 1.

Abstract

The purpose of this study was to investigate the in vitro effects of vegetable carbohydrates on the activity of microbial β-glucuronidase (βG) 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 βG from Escherichia coli was determined spectrophotometrically by the formation of the colored product from the breakdown of phenolphthalein-β-D-glucuronide. Adsorption of βG 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 βG by 50 and 100%, respectively. Cellulose had a weak effect, whereas pepper PPC had no effect. All studied carbohydrates adsorb on βG. The maximum βG 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 βG 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+βG 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Brassica / chemistry
  • Capsicum / chemistry
  • Digestion
  • Escherichia coli / enzymology
  • Estrogens / metabolism
  • Glucuronidase / metabolism*
  • Pectins / metabolism*
  • Pectins / pharmacology*
  • Plant Proteins / metabolism
  • Plant Proteins / pharmacology
  • Vegetables / chemistry*

Substances

  • Estrogens
  • Plant Proteins
  • Pectins
  • Glucuronidase