Abstract

The """"""""dual probe method"""""""" for measuring surface potentials of biological membranes will be expanded to treat intra-membrane (""""""""dipole"""""""") potentials. Factors promoting or inhibiting the permeability of mitochondrial and other membranes to charged amphiphilic spin probes will be characterized. The dispersion of activities of proton pumping vesicles will be estimated with spin labeled weak acids and amines and related to maximum (""""""""threshold"""""""") potentials. The biological significance of free radical reactions causing nitroxide destruction in illuminated inner mitochondrial membranes will be further characterized.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG004818-06
Application #
3115373
Study Section
Physical Biochemistry Study Section (PB)
Project Start
1983-09-29
Project End
1986-08-31
Budget Start
1985-09-01
Budget End
1986-08-31
Support Year
6
Fiscal Year
1985
Total Cost
Indirect Cost

  Institution

Name
Lawrence Berkeley National Laboratory
Department
Type
Organized Research Units
DUNS #
078576738
City
Berkeley
State
CA
Country
United States
Zip Code
94720

  Publications

Moore, K L; Mehlhorn, R J (1993) Cytostatic effects of horseradish and thyroid peroxidase derived free radicals. Free Radic Biol Med 14:371-9
Moore, K L; Moronne, M M; Mehlhorn, R J (1992) Electron spin resonance study of peroxidase activity and kinetics. Arch Biochem Biophys 299:47-56
Mehlhorn, R J (1991) Ascorbate- and dehydroascorbic acid-mediated reduction of free radicals in the human erythrocyte. J Biol Chem 266:2724-31
Prolla, T A; Mehlhorn, R J (1990) A photochemical system for generating free radicals: superoxide, phenoxyl, ferryl and methyl. Free Radic Res Commun 9:135-46
Mehlhorn, R J; Fuchs, J; Sumida, S et al. (1990) Preparation of tocopheroxyl radicals for detection by electron spin resonance. Methods Enzymol 186:197-205
Fuchs, J; Mehlhorn, R J; Packer, L (1989) Free radical reduction mechanisms in mouse epidermis skin homogenates. J Invest Dermatol 93:633-40
Packer, L; Maguire, J J; Mehlhorn, R J et al. (1989) Mitochondria and microsomal membranes have a free radical reductase activity that prevents chromanoxyl radical accumulation. Biochem Biophys Res Commun 159:229-35
Mehlhorn, R J; Sumida, S; Packer, L (1989) Tocopheroxyl radical persistence and tocopherol consumption in liposomes and in vitamin E-enriched rat liver mitochondria and microsomes. J Biol Chem 264:13448-52
Todd, A P; Mehlhorn, R J; Macey, R I (1989) Amine and carboxylate spin probe permeability in red cells. J Membr Biol 109:41-52
Todd, A P; Mehlhorn, R J; Macey, R I (1989) Amine spin probe permeability in sonicated liposomes. J Membr Biol 109:53-64

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