abstract        background and objective: peroxidases catalyze protein oxidation and lipid peroxidation. the activity of these enzymes in nerve cells is involved in causing disorders such as alzheimer's and parkinson's disease. this study investigated the effect of citrus aurantium, foeniculum vulgare and rosmarinus officinalis essential oils on activity of peroxidase enzyme.       me...

It is known that surface structural relaxation takes place more rapidly than bulk structural relaxation, especially in the presence of water vapor. The surface structural relaxation kinetics of the silica glass fiber and plates was compared at 950 C and the surface structural relaxation kinetics of silica glass fiber was found to be faster than that of the silica glass plate, even though the co...

Sodium currents in fast firing neurons are tuned to support sustained firing rates >50-60 Hz. This is typically accomplished with fast channel kinetics and the ability to minimize the accumulation of Na channels into inactivated states. Neurons in the medial vestibular nuclei (MVN) can fire at exceptionally high rates, but their Na currents have never been characterized. In this study, Na curre...

we have investigated the effect of theophylline on the kinetics of the catalytic subunit of protein kinase and related factors in lung tissue. the results show that the point of highest concentration of the c subunit of protein kinase which is active in casein phosphorylation is at 3h of incubation time, but in the presence of 100 ilg/ inl and 10µg/ml theophylline, this is shifted to i.s and 2....

Protoglobin from Methanosarcina acetivorans (MaPgb) is a dimeric globin with peculiar structural properties such as a completely buried haem and two orthogonal tunnels connecting the distal cavity to the solvent. CO binding to and dissociation from MaPgb occur through a biphasic kinetics. We show that the heterogenous kinetics arises from binding to (and dissociation from) two tertiary conforma...

We analyse the dynamics of overlapping antiparallel treadmilling microtubules in the presence of crosslinking processive motor proteins that counterbalance an external force. We show that coupling the force-dependent velocity of motors and the kinetics of motor exchange with a bath in the presence of treadmilling leads generically to oscillatory behavior. In addition we show that coupling the p...

The intergenic IRES of Cricket Paralysis Virus (CrPV-IRES) forms a tight complex with 80S ribosomes capable of initiating the cell-free synthesis of complete proteins in the absence of initiation factors. Such synthesis raises the question of what effect the necessary IRES dissociation from the tRNA binding sites, and ultimately from all of the ribosome, has on the rates of initial peptide elon...

The survival of the malaria parasite Plasmodium falciparum is dependent upon the de novo biosynthesis of pyrimidines. P. falciparum dihydroorotate dehydrogenase (PfDHODH) catalyzes the fourth step in this pathway in an FMN-dependent reaction. The full-length enzyme is associated with the inner mitochondrial membrane, where ubiquinone (CoQ) serves as the terminal electron acceptor. The lipophili...

We applied the so-called chemical kinetics approach to complex bacterial growth patterns that were dependent on the liquid-surface-area-to-volume ratio (SA/V) of the bacterial cultures. The kinetic modeling was based on current experimental knowledge in terms of autocatalytic bacterial growth, its inhibition by the metabolite CO2, and the relief of inhibition through the physical escape of the ...