In the present study, 110 fungal strains of Persian Type Culture Collection (PTCC) including some selected strains isolated in various screening projects were tested for their potentiality to produce lovastatin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reduc-tase), the rate-limiting enzyme of cholesterol biosynthesis. The fungal strains were cultivated in a t...

Using wheat germ acid phosphatase and sodium orthovanadate as a competitive inhibitor, a novel method for analyzing reversible inhibition was carried out. Our alternative approach involves plotting the initial velocity at which product is formed as a function of the ratio of substrate concentration to inhibitor concentration at a constant enzyme concentration and constant assay conditions. The ...

The competitive inhibitor cocaine and the non-competitive inhibitor ibogaine induce different conformational states of the human serotonin transporter. It has been shown from accessibility experiments that cocaine mainly induces an outward-facing conformation, while the non-competitive inhibitor ibogaine, and its active metabolite noribogaine, have been proposed to induce an inward-facing confo...

BACKGROUND cAMP-dependent protein kinase (PKA) has been implicated in the asexual stage of the Toxoplasma gondii life cycle through assaying the effect of a PKA-specific inhibitor on its growth rate. Since inhibition of the host cell PKA cannot be ruled out, a more precise evaluation of the role of PKA, as well as characterization of the kinase itself, is necessary. METHODOLOGY/PRINCIPAL FIND...

We previously reported that some ATP competitive protein kinase C (PKC) inhibitors are either competitive or uncompetitive inhibitors with respect to substrate peptides. In this report, we demonstrate how the interactions between PKC and inhibitors change PKC activation kinetics. A substrate competitive inhibitor, bisindolylmaleimide I, targets activated PKC and stabilizes PKC in the activated ...

abstract background and objective: highly active antiretroviral therapy (haart) can effectively prevent the progression of hiv-1 replication and increase life expectancy. there are numerous causes of treatment failure and the leading one is drug resistance. thus, we aimed to determine the hiv rt gene drug resistance mutations in patients treated with antiretroviral medications. material and met...

1. Kinetic investigations of the reaction catalysed by ATP-creatine phosphotransferase have been carried out. 2. No firm conclusions could be reached about the reaction of Mg(2+) at the nucleotide-binding site of the enzyme. The value of the kinetic constant for this reaction depends on the value used for the apparent stability constant of the metal ion-nucleotide complex and, to a smaller exte...

1. Kinetic measurements of the forward reaction catalysed by ATP-galactose phosphotransferase were carried out with a purified preparation from pig liver. 2. The rate of reaction at pH7.8 is dependent on the concentration of MgATP(2-) rather than total ATP or magnesium chloride concentrations. 3. The effect of changes in pH on K(m) (galactose), K(m) (MgATP(2-)) and V(max.) was studied. 4. Of se...