Interfacial charge separation in photoreceptor memebranes.
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Animals↗
Biomedical subjects
D S Cafiso
Publications and source records attributed to D S Cafiso.
Estimation of transmembrane pH gradients from phase equilibria of spin-labeled amines.
Spin-labeled secondary amines have been used to measure transmembrane proton gradients in sonicated liposomes. The electron paramagnetic resonance spectra of these probes show changes in the ratio of membrane associated to free aqueous probe as a function of transmembrane pH gradient. As the pH gradient is increased, inside acidic, the amount of membrane associated probe increases. The results are accounted for by a simple thermodynamic theory.
Amines↗
Estimation of transmembrane potentials from phase equilibria of hydrophobic paramagnetic ions.
Positively charged hydrophobic spin labels have been synthesized which respond to transmembrane potentials in sonicated liposomes. Electron paramagnetic resonance spectroscopy is used to show that the distribution of these probes between aqueous and membrane phases changes as a function of transmembrane potential. When liposomes are made more inside-negative, the fraction of membrane associated probe increases while the fraction of probe in the aqueous phase decreases. The results are in quantitative agreement with a simple equilibrium thermodynamic theory which allows estimation of absolute transmembrane potentials in phospholipid vesicles.
Electron Spin Resonance Spectroscopy↗