An important elimination route of the histamine H2 antagonist famotidine is active tubular secretion via the renal organic cation transport system. To characterize the excretion kinetics of famotidine in-vivo, the relationship between plasma concentration and urinary excretion rate was investigated in the beagle dog over a wide concentration range. The maximum transport capacity and the apparen...

Sucralose, one of the popular non-caloric artificial sweeteners, has been known to influence enzymatic conversion sucrose glucose and fructose by invertase. In continuing use real-time NMR experiments reaction progress curve analysis measure enzyme kinetics, here we investigate role sucralose as an inhibitor. based kinetic were performed a function substrate concentration for range concentratio...

Enzymes are dynamic entities: both their conformation and catalytic activity fluctuate over time. When such fluctuations are relatively fast, it is not surprising that the classical Michaelis-Menten (MM) relationship between the steady-state enzymatic velocity and the substrate concentration still holds. However, recent single-molecule experiments have shown that this is the case even for an en...

Digestion of chromatin in nuclei by micrococcal nuclease, measured as the change in the concentration of monomer-length DNA with time, displays Michaelis-Menten kinetics. Redigestion of soluble chromatin prepared from nuclei by micrococcal nuclease treatment, however, is apparently first order in enzyme and independent of chromatin concentration. This qualitative difference results from an incr...

-1. The effects of osmolarity on the maximal velocity (Vmax) and apparent Michaelis constant (K~) for the oxidation of proline by both intact and sonicated mitochondria from the ventricle of the marine clam Mercenaria mercenaria have been determined. 2. Compared to the isoosmotic state (1040mOsm/I), the rate of oxidation at any concentration of proline by intact mitochondria is greater in the h...

The cytosol of a cell is a concentrated milieu of a variety of different molecules, including small molecules (salts and metabolites) and macromolecules such as nucleic acids, polysaccharides, proteins and large macromolecular complexes. Macromolecular crowding in the cytosolic environment is proposed to influence various properties of proteins, including substrate binding affinity and enzymati...

An average of 11 (range, 2 to 47) mumoles of formate per g per hr was produced and used in whole bovine rumen contents incubated in vitro, as calculated from the product of the specific turnover rate constant, k, times the concentration of intercellular formate. The latter varied between 5 and 26 (average, 12) nmoles/g. The concentration of formate in the total rumen contents was as much as 1,0...

Background and Aim: One of the key aspects of maternal care is observing the progress of labor. Careful assessment of labor progress could provide mothers to be referred on time and could decrease the maternal and neonatal morbidity. This study aimed to compare diagnostic accuracy of purple line with transvers diagonal of Michaelis sacral rhomboid to predict labor progress in nulliparous and mu...

A Penicillium camemberti strain isolated in our laboratory has been studied for its ability to degrade chlorinated pulping wastes, presumably containing a variety of chlorinated polyphenols. In batch tests, the highest removals (76% AOX, 61% color and 65% TOC) were obtained with 0.2 g/l feed acetate concentration. The tendency of the fungus to dechlorinate bleachery effluents better under non-s...