dose-dependent pharmacokinetic of phenytoin necessitates the estimation of the maximum rate of metabolism (vm) and the michaelis-menten constant (km) in a concerned population. the aim of this study was to determine the pharmacokinetic parameters of phenytoin in a sample of iranian patients to optimize the antiepileptic pharmacotherapy. fourty patients who received a constant dose of phenytoin ...

in present study, the kinetic parameters of purified trypsin from pyloric caeca of common kilka (c.cultriventris caspia) were measured using the amidolytic (bapna) and esterolytic (tame) substrates. the results of the kinetic comparison between bapna and tame substrates showed that kinetic parameters including maximum velocity (vmax), catalytic constant (kcat) and catalytic efficiency (kcat/km)...

The electrocatalytic oxidation of vitamin B6 (pyridoxine hydrochloride) was demonstrated on a Nafion/lead ruthenate pyrochlore modified electrode (designated as NCME) by cyclic voltammetry. The catalytic activity of vitamin B6 was explored in terms of the higher oxidation state of ruthenium species, i.e., Py-Ru/Ru in the pyrochlore network (Py). The mediated mechanism was derived by Michaelis-M...

Enzyme kinetics are usually described by the Michaelis-Menten equation, where the time-dependent decrease of substrate (-dS/dt) is a hyperbolic function of maximal velocity (Vmax), Michaelis constant (Km), and amount of substrate (S). Because the Michaelis-Menten function in its most general meaning requires an assumption of steady-state, it is less curvilinear than true enzyme kinetics. A satu...

Dose-dependent pharmacokinetic of phenytoin necessitates the estimation of the maximum rate of metabolism (Vm) and the Michaelis-Menten constant (Km) in a concerned population. The aim of this study was to determine the pharmacokinetic parameters of phenytoin in a sample of Iranian patients to optimize the antiepileptic pharmacotherapy. Fourty patients who received a constant dose of phenytoin ...

Dose-dependent pharmacokinetic of phenytoin necessitates the estimation of the maximum rate of metabolism (Vm) and the Michaelis-Menten constant (Km) in a concerned population. The aim of this study was to determine the pharmacokinetic parameters of phenytoin in a sample of Iranian patients to optimize the antiepileptic pharmacotherapy. Fourty patients who received a constant dose of phenytoin ...

Root influx parameters (Vmax and Km) of wheat (Triticum aestivum var. HD-2285) were determined at different stages of crop growth, viz. CRIS-Crown Root Initiation Stage, MTS-Maximum Tillering Stage, FLS-Flag Leaf Stage and DFS-Dough Formation Stage. Wheat was grown in sand medium with Hoagland nutrient solution (all nutrients except potassium). Plants were taken out from sand culture at 22, 41,...

A biodegradable polyester resin was polymerized from N-benzyloxycarbonylL -glutamic acid and ethylene glycol. Rhizopus delemar lipase was used as a biocatalyst for the rupture of ester bonds during the hydrolysis studies. Depolymerization was observed to followa Michaelis–Menten mechanism, with the maximumrate of monomer formation dP/dtmax = 1.12 x 10-8 mol/s and the rate constant Km x 2.03 x 1...

The effect of hypothermia on the in vivo pharmacokinetics of midazolam was evaluated, with a focus on altered metabolism in the liver and binding to serum proteins. Rat primary hepatocytes were incubated with midazolam (which is metabolized mainly by CYP3A2) at 37, 32 or 28 °C. The Michaelis-Menten constant (Km) and maximum velocity (Vmax) of midazolam were estimated using the Michaelis-Menten ...

The main objective of this study was to purify and characterize an esterase from Shewanella sp F88. The enzyme was purified 41-fold and an overall yield of 21 %, using a two-step procedure, including ammonium sulfate precipitation and Q-sepharore chromatography. Molecular weight of the enzyme was 62.3 kDa according to SDS-PAGE data. The enzyme showed an optimum activity at pH 6.5 and 58 ˚C. Evo...