Cinatrins A, B and C3 inhibited phospholipase A2 purified from rat platelets in a dose-dependent manner. Cinatrin C3, the most potent component (IC50 70 microM), was noncompetitive with a Ki value of 36 microM. Cinatrins B and C3 also inhibited both porcine pancreas and Naja naja venom phospholipase A2. Inhibition of rat platelet phospholipase A2 by cinatrin C3 was independent of Ca2+ and subst...

AIMS The possibility of substrate inhibition by glucose on biomass and pediocin production was studied in cultures of Pediococcus acidilactici on a residual medium. METHODS AND RESULTS Calculation of the substrate inhibition coefficient in the context of microbial growth is generally laborious, and very prone to experimental error. However, a simulation combining logistic and Monod kinetics e...

T h e commonly used trypsin substrate Na-benzoyl-m.arginine p-naphthylamide ( B A N A ) was not cleaved by either GB or SCTPA. BANA caused 50% inhibition of G B at 2 x 1 0 F J M when assayed with MUGB, and 50% inhibition of SCTPA at lo-’ M when assayed with substrate S-2288. We conclude that the proteinases SCTPA and GB (although not necessarily identical) are more closely related t o each othe...

Protoporphyrin IX ferrochelatase (EC 4.99.1.1) catalyzes the terminal step in the heme biosynthetic pathway, the insertion of ferrous iron into protoporphyrin IX. Ferrochelatase shows specificity, in vitro, for multiple metal ion substrates and exhibits substrate inhibition in the case of zinc, copper, cobalt, and nickel. Zinc is the most biologically significant of these; when iron is depleted...

The kinetics of purified bovine hepatic fructose 1,6-diphosphatase have been examined at physiological PH. The enzyme is inhibited by high concentrations of both its substrate, fructose 1,6-diphosphate (Fru-1 ,6-Pz), and its cofactor magnesium. Magnesium inhibits at noninhibitory Fru-1,6-Pz concentrations, but at inhibitory substrate concentrations, magnesium activates rather than inhibits. Mag...

Lactiplantibacillus plantarum is a Gram-positive bacterium that belongs to the lactic acid bacteria (LAB) group commonly used in food industry. To use this microorganism, high biomass concentration necessary, and models need be established for predicting improving its behavior along fermentation. However, current L. are applicable only one substrate. The growth of newly isolated strain 60-1 co-...

Biodegradation of phenol in the presence of glucose as a supplementary substrate was investigated with mixed microbial consortium isolated from waste effluent of coke-steel factory. Batch experiments were carried out at room temperature and pH value of 7. Initial phenol and glucose concentrations were in the range of 25-1000 mg/l and 500-3000 mg/l, respectively. In a dual substrates system the ...

The influence of substrate and enzyme concentrations on the rate of saccharification of two defined insoluble cellulose substrates, Avicel (FMC Corp., Philadelphia, Pa.) and Solka-Floc (James River Co., Berlin, N.H.), by the cellulase enzyme system of Trichoderma viride was evaluated. In the assays, enzyme concentrations ranging from 0.004 to 0.016 IU/ml and substrate concentrations up to 10% (...

The selection of appropriate substrates for investigating the potential inhibition of CYP3A4 is critical as the magnitude of effect is often substrate-dependent, and a weak correlation is often observed among different CYP3A4 substrates. This feature has been attributed to the existence of multiple binding sites and, therefore, relatively complex in vitro data modeling is required to avoid erro...