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Your search keyword '"Estrada, O."' showing total 6 results
Start Over Author "Estrada, O." Journal journal of bioenergetics
6 results on '"Estrada, O."'

4. Charge transfer mediated by nigericin in black lipid membranes

Author

Mireya Toro, Carlos Gómez-Lojero, M. Montal, and Sergio Estrada-O

Subjects
endocrine system, Nigericin, Physiology, Dimer, Electric Conductivity, Ionophore, Conductance, Membranes, Artificial, Protonation, Cell Biology, Hydrogen-Ion Concentration, Models, Biological, Orders of magnitude (mass), Anti-Bacterial Agents, Mitochondria, chemistry.chemical_compound, Crystallography, Membrane, chemistry, Phosphatidylcholines, Potassium, Biophysics, Lipid bilayer
Abstract

Nigericin, in the concentration range (10(-6) M or higher) at which it uncouples intact mitochondria, was found to increase the conductance of black lipid membranes (BLM) by several orders of magnitude. The dependence of the membrane conductance on pH and K+ concentration suggests a mechanism for the transfer of charge mediated by this ionophore based on a mobile dimer with both nigericin molecules protonated and complexed with one K+. This charged complex accounts for the uncoupling effect observed in intact mitochondria.

Published
1976
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5. Specific inhibition by macrocyclic polyethers of mitochondrial electron transport at site I

Author

Alfonso Cárabez and Sergio Estrada-O

Subjects
Isocitrates, Vitamin K, Physiology, Polymers, Malates, Cesium, Mitochondria, Liver, Saccharomyces cerevisiae, In Vitro Techniques, Mitochondrial electron transport, Medicinal chemistry, Electron Transport, Glutamates, ATP hydrolysis, Cyclohexanes, Ethers, Cyclic, Benzene Derivatives, Organic chemistry, Bioorganic chemistry, Animals, Pyruvates, Valinomycin, Chemistry, Myocardium, Glutamate receptor, Cell Biology, Mitochondria, Mitochondria, Muscle, Rats, Potassium, Ketoglutaric Acids, Cattle
Abstract

The macrocyclic polyethers dibenzo-18-crown-6 (XXVIII) and dicyclohexyl-18-crown-6 (XXXI) inhibit the valinomycin-mediated K+ accumulation energized by glutamate, α-ketoglutarate, malate plus pyruvate or isocitrate but not that promoted by succinate, ascorbate plus TMPD or ATP. The polyethers inhibit the oxidation of the former group of substrates without preventing either the oxidation of succinate or ascorbate plus TMPD or the hydrolysis of ATP.

Published
1972

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