Daptomycin (LY146032) caused a calcium-dependent dissipation of the membrane potential (delta psi) in Staphylococcus aureus without noticeably affecting the chemical gradient (delta pH) across the membrane. The effect of daptomycin on membrane energization may account for many of the inhibitory effects on macromolecular biosyntheses and membrane function reported for this antibiotic. Our eviden...

We describe a quantum algorithm that solves combinatorial optimization problems by quantum simulation of a classical simulated annealing process. Our algorithm exploits quantum walks and the quantum Zeno effect induced by evolution randomization. It requires order 1/sqrt delta steps to find an optimal solution with bounded error probability, where delta is the minimum spectral gap of the stocha...

The effect of three food preservatives, sorbic acid and methyl and butyl esters of p-hydroxybenzoic acid, on the protonmotive force in Escherichia coli membrane vesicles was investigated. Radioactive chemical probes were used to determine the two components of the protonmotive force: delta pH (pH difference) and delta psi (membrane potential). Both types of compound selectively eliminated delta...

Valinomycin, nigericin and trichlorocarbanilide were assessed for their ability to control the protonmotive force in Escherichia coli cells. Valinomycin, at high K+ concentrations, was found to decrease the membrane potential delta phi and indirectly to decrease the pH gradient delta pH. Nigericin was found to have two modes of action. At low concentrations (0.05-2 microM) it carried out K+/H+ ...

The orientational effect of p-YC(6)H(4) (Ar) on delta(Se) is elucidated for ArSeR, based on experimental and theoretical investigations. Sets of delta(Se) are proposed for pl and pd employing 9-(arylselanyl)anthracenes (1) and 1-(arylselanyl)anthraquinones (2), respectively, where Se-C(R) in ArSeR is on the Ar plane in pl and perpendicular to the plane in pd. Absolute magnetic shielding tensors...

Recent studies have shown that protein kinase C (PKC) delta is proteolytically activated at the onset of apoptosis induced by DNA-damaging agents, tumor necrosis factor, and anti-Fas antibody. However, the relationship of PKC delta cleavage to induction of apoptosis is unknown. The present studies demonstrate that full-length PKC delta is cleaved at DMQD330N to a catalytically active fragment b...

The effects of enkephalins selective for delta and mu opioid receptors on inhibitory postsynaptic currents (IPSCs) mediated by GABA were studied in chloride-loaded CA1 pyramidal neurons in adult rat hippocampal slices. The mu agonist DAMGO (0.1 microM) significantly reduced the amplitudes of evoked monosynaptic IPSCs, recorded following the antagonism of excitatory glutamate receptors, and this...

1 A multi-year study in the Sacramento-San Joaquin Delta system was carried out to exam2 ine the relationship between the survival of out-migrating Chinook salmon Oncorhynchus 3 tshawytscha and the amount of water exported from the system by the two major pumping 4 stations in the southern portion of the Delta. Paired releases of groups of coded-wire-tagged 5 juvenile late-fall run Chinook salm...

The theory of pleiotropic mutation and selection is investigated and developed for a large population of asexual organisms. Members of the population are subject to stabilising selection on Omega phenotypic characters, which each independently affect fitness. Pleiotropy is incorporated into the model by allowing each mutation to simultaneously affect all characters. To expose differences with c...

Using the distribution of weak acids to measure the pH gradient (delta pH; interior alkaline) and the distribution of the lipophilic cation [3H]tetraphenylphosphonium+ to monitor the membrane potential (delta psi; interior negative), we studied the electrochemical gradient or protons (delta mu- H+) across the membrane of Micrococcus lysodeikticus cells and plasma membrane vesicles. With reduced...