4-Arsono-2-hydroxybutanoic acid, the analogue of 3-phosphoglycerate in which -CH2-AsO3H2 replaces -O-PO3H2, was synthesized. It proved to be a substrate for phosphoglycerate kinase. Its Michaelis constant was only slightly higher than that of the natural substrate, but its catalytic constant was about 1300 times smaller.

Nitrite reductase from Escherichia coli K12 requires the presence of NAD+, one of the products of the reduction ofNO2by NADH, for full activity. The effect is observed with both crude extracts and purified enzyme. NAD+ also acts as a product inhibitor at high concentrations, and plots of initial rate against NAD+ concentration are bell-shaped. The maximum occurs at about 1 mM-NAD+, but increase...

A method based on the rate of depletion of a nutrient from solution was developed to characterize nutrient flux of plant roots. Nutrient concentration of the solution was measured at a series of time intervals to describe the complete depletion curve. An integrated rate equation, based on a Michaelis-Menten model, was developed and fit to the data of the depletion curve using a least-square pro...

BACKGROUND Our study was based on the alteration in the Michaelis Mentin parameters Apparent Michaelis Constant (aKm) and Apparent Maximum Velocity (aVm), which reflects activity of actylcholinesterase (AChE). This activity decreases in Acute Lymphoblastic Leukaemia (ALL). This decrease in aKm and aVm values shows bad prognosis. Similarly the anticancer drugs like Daunorubicin and Doxorubicin f...

Intravenous injections of n-propanol (25 mg, 50 mg, 100 mg, 200 mg, 300 mg) provoke blood concentration curves having exponential shapes of dose dependent rate constants after a sufficiently long time (2 min). They have to be seen therefore as a result of a non-linear elimination process controlled by a Michaelis-Menten-kinetic. Using the Lineweaver-Burk-method the characteristic data of metabo...

A novel FAD-dependent glucose dehydrogenase (FAD-GDH) was found and its enzymatic property for glucose sensing was characterized. FAD-GDH oxidized glucose in the presence of some artificial electron acceptors, except for O2, and exhibited thermostability, high substrate specificity and a large Michaelis constant for glucose. FAD-GDH was applied to an amperometric glucose sensor with Fe(CN)6(3-)...

A self-assembled supramolecular complex is reported to catalyze alkyl-alkyl reductive elimination from high-valent transition metal complexes [such as gold(III) and platinum(IV)], the central bond-forming elementary step in many catalytic processes. The catalytic microenvironment of the supramolecular assembly acts as a functional enzyme mimic, applying the concepts of enzymatic catalysis to a ...

This paper summarizes our present theoretical understanding of single-molecule kinetics associated with the Michaelis-Menten mechanism of enzymatic reactions. Single-molecule enzymatic turnover experiments typically measure the probability density f(t) of the stochastic waiting time t for individual turnovers. While f(t) can be reconciled with ensemble kinetics, it contains more information tha...