The temperature dependence of the rate constant for substrate oxidation by the dehaloperoxidase-hemoglobin (DHP) of Amphitrite ornata has been measured from 278 to 308 K. The rate constant is observed to increase over this range by approximately a factor of 2 for each 10 °C temperature increment. An analysis of the initial rates using a phenomenological approach that expresses the peroxidase pi...

effects of atp and mg2+ concentrations on bioluminescence reaction of luciferase (photinus pyralis) were investigated by home-made luminometer. the michaelis constants of the enzyme for atp and mg2+ obtained from the lineweaver-burk graph, were 61.9 mm ±3.3 mm and 251.6mm ± 39.0mm respectively. optimum concentration of mg2+ for maximum luminescence was 0.004 m.

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 ...

Matched pairs of malignant and non-malignant hybrid cells were compared in their response to glucose deprivation and to tunicamycin. Glucose deprivation induced an increase in the maximum velocity in the malignant cells, but not in the non-malignant cells. The Michaelis constant of hexose uptake was largely unchanged by glucose deprivation except in the case of one melanoma derivative, PG19 G-,...

Often the Michaelis constant of an enzyme will be determined several times. This may be done for various reasons such as ensuring reproducibility, comparing different enzyme preparations, or examining the effects of variations in experimental conditions. In these circumstances, two questions arise. First, how can the various estimates of the Michaelis constant be compared to determine whether t...

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...