Two menaquinone-deficient and one aromatic-deficient mutants of Staphylococcus aureus were unable to reduce nitrate to nitrite. Reinitiation of menaquinone synthesis in the aromatic-deficient mutant by growing it with shikimic acid restored its nitrate respiratory activity. The results clearly demonstrate a role for menaquinone in nitrate respiration in Staphylococcus aureus.

although inter-variety variability for salt tolerance has been reported in bread wheat plants, little information is available on the genetic control of ion contents and biomass yield under saline conditions. a diallel cross, including reciprocals of two salt tolerant, two moderately tolerant and two sensitive iranian and exotic bread wheat varieties, was analyzed to investigate the inheritance...

In this work, the results relating to the mean activity coefficient measurements for ionic liquid of 1- propyl -3 methylimidazolium bromide, [PMIm]Br in ethanol+ water mixtures have been reported using potentiometric measurements at T=( 298.2, 308.2 and 318.2)K. The electromotive force (emf) measurements were performed on the galvanic cell of the type:Br-ISE│[PrMIm] (m) ethanol (wt.%), H2O (1−w...

There is a limited number of reports regarding detergents and proteases inactivating, degrading, or destabilizing abnormal prion protein (PrPSc). In the present study, the effect of alkaline detergents and proteases on the breakdown of PrPSc in the absence of proteinase K (PK) (degradation) and the presence of PK (destabilization) was investigated. PrPSc from brain homogenate of terminally-dise...

Net sodium influx under K-free conditions was independent of the intracellular sodium ion concentration, [Na](i), and was increased by ouabain. Unidirectional sodium influx was the sum of a component independent of [Na](i) and a component that increased linearly with increasing [Na](i). Net influx of sodium ions in K-free solutions varied with the external sodium ion concentration, [Na](o), and...

Permeant ion species was found to profoundly affect the gating kinetics of type l K+ currents in mouse T lymphocytes studied with the whole-cell or on-cell patch gigaohm-seal techniques. Replacing external K+ with Rb+ (as the sole monovalent cation, at 160 mM) shifted the peak conductance voltage (g-V) relation by approximately 20 mV to more negative potentials, while NH4+ shifted the g-V curve...

The rates of addition of molecular bromine in acetic acid to a number of acetylenes have been found to follow the general equation d(Br,)/dt = [acetylene](k, [Br,] + k3 [Br212 + k,,[Br,] [Br1) In the absence of bromide ion and at low bromine concentrations (< 2 x M), only the k 2 process is observable. These k 2 values for a series of ring-substituted phenylacetylenes are correlated well with o...

In principle, an ion channel needs no more than a single gate, but a pump requires at least two gates that open and close alternately to allow ion access from only one side of the membrane at a time. In the Na+,K+-ATPase pump, this alternating gating effects outward transport of three Na+ ions and inward transport of two K+ ions, for each ATP hydrolysed, up to a hundred times per second, genera...

Platelet plasma membrane vesicles accumulate 5-hydroxytryptamine in response to a gradient of NaCl (out > in). Although potassium ion is not required for this process, a K’ concentration gradient (in > out) elevates the steady state level of 5-hydroxytryptamine accumulation 5-fold. Transport is independent of the generation of an electrical potential (interior negative) across the vesicle membr...