The initial rate of formation of chlorine dioxide in the chlorite-tetrathionate reaction changes in an unusual fashion. The formal kinetic order of both reactants varies over a very wide range. Moreover, chlorite ion behaves not just as a simple reactant, but also as a self-inhibitor. A five-step scheme, derived from an eight-step mechanism, is proposed in which the autocatalytic formation of H...

o-Carbonyl arylboronic acids such as 2-formylphenylboronic acid (2-FPBA) are employed in biocompatible conjugation reactions with the resulting iminoboronate adduct stabilized by an intramolecular N–B interaction. However, few studies have utilized these reagents active site-directed enzyme inhibitors. We show that 2-FPBA is a potent reversible, slow-onset inhibitor of mandelate racemase (MR), ...

Large variations of the maximal rate of aldehyde reduction by liver alcohol dehydrogenase and reduced nicotinamide adenine dinucleotide (NADH) showed that commercial preparations of this coenzyme contain variable amounts of an inhibitor (1). The observed kinetic effects were reproduced quantitatively by a known competitive inhibitor, adenosine diphosphate ribose, added in constant molar ratio t...

Computer simulations of the irreversible inhibition of an enzyme by an unstable inhibitor are presented. Data obtained at the end point of reaction are shown to conform poorly in many situations with relationships derived from integrated rate equations by setting t = infinity, and the implications concerning the experimental use of this method to determine kinetic constants describing inactivat...

In the present study, we characterized the kinetic parameters of 7-ethoxy-resorufin O-deethylation (EROD) and 7-methoxyresorufin O-demethylation (MROD) in hepatic microsomes from entire and castrated male pigs. Validation parameters of an HPLC-based method to analyse EROD and MROD activities are also described. Eadie-Hofstee plot analysis demonstrated a biphasic kinetic of EROD, indicating that...

The aim of this study was to examine in vitro, by means of kinetic analysis and molecular docking simulations, the effects of the flavone diosmetin and its flavanone analog hesperetin on CYP (cytochrome P450) 2C9-mediated drug metabolism. To this purpose, the conversion of diclofenac to 4'-hydroxydiclofenac by human liver microsomes was used as a model assay for assessing the CYP2C9 inhibitory ...

It is shown that kinetic control dissociation of a complex prepared by mixing of equimolar quantities of trypsin and of modified (reactive site Arg (64)-Ile bond cleaved) soybean trypsin inhibitor (Kunitz) yields trypsin and predominantly ( >95%) virgin (reactive site intact) inhibitor. I f less than equimolar quantities of trypsin are used the fraction of inhibitor molecules in which the bond ...

In this study, the two aqueous extracts from aerial parts of Aaronsohnia pubescens subsp. (Odorized extract (OE) and Deodorized (DE)) were used as some novel ecological corrosion inhibitors for mild steel (MS) in 1 M HCl medium. For reason, inhibition behavior OE DE having investigated using weight loss measurements, electrochemical assays, kinetic thermodynamic parameters, methods both station...

A new method is described for plotting kinetic results for inhibited enzyme-catalysed reactions. It provides a simple way of determining the inhibition constant, K'(i), of an uncompetitive, mixed or non-competitive inhibitor.