title: Interaction of microbial β-glucuronidase with vegetable pectins.
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.
authors.affiliation: Institute of Physiology, Komi Science Center, Urals Branch of the Russian Academy of Science, Syktyvkar, Russia. borisenkov@physiol.komisc.ru
authors.forename: Mikhail F
authors.initials: MF
authors.lastname: Borisenkov
authors.forename: Larissa A
authors.initials: LA
authors.lastname: Bakutova
authors.forename: Dmitry S
authors.initials: DS
authors.lastname: Latkin
authors.forename: Victoria V
authors.initials: VV
authors.lastname: Golovchenko
authors.forename: Fedor V
authors.initials: FV
authors.lastname: Vityazev
mesh_terms: D000327:Adsorption; D001937:Brassica / Q000737:chemistry; D002212:Capsicum / Q000737:chemistry; D004063:Digestion; D004926:Escherichia coli / Q000201:enzymology; D004967:Estrogens / Q000378:metabolism; D005966:Glucuronidase / Q000378:metabolism*; D010368:Pectins / Q000378:metabolism* / Q000494:pharmacology*; D010940:Plant Proteins / Q000378:metabolism / Q000494:pharmacology; D014675:Vegetables / Q000737:chemistry*
chemical_list: D004967:Estrogens; D010940:Plant Proteins; D010368:Pectins; D005966:Glucuronidase