Abstract

Taking advantage of the increased spectral resolution offered by the W-band ESR spectrometer, we have examined, at pH 7 and pH 12, ESR spectra of human RPE's of young, intermediate and old individuals. The data show remarkable changes in ESR signal of the human RPE with age. Interestingly, distinct changes in the magnetic parameters of the W-band ESR signal of RPE can be detected as early as in the second decade of the human life. Since purified melanosomes isolated from RPE's, exhibited ESR signals with spectral parameters identical to those of the corresponding RPE cells, we may conclude that the observed ESR signal is entirely due to these cells melanin. While we have not identified yet the molecular nature of the observed paramagnetic changes with aging, it is probable that they indicate significant modification of the melanin structure.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Center for Research Resources (NCRR)
Type
Biotechnology Resource Grants (P41)
Project #
2P41RR001811-11
Application #
5223658
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
11
Fiscal Year
1996
Total Cost
Indirect Cost

  Publications

Hurth, Kyle M; Nilges, Mark J; Carlson, Kathryn E et al. (2004) Ligand-induced changes in estrogen receptor conformation as measured by site-directed spin labeling. Biochemistry 43:1891-907
Woodmansee, Anh N; Imlay, James A (2002) Reduced flavins promote oxidative DNA damage in non-respiring Escherichia coli by delivering electrons to intracellular free iron. J Biol Chem 277:34055-66
Denisov, Ilia G; Makris, Thomas M; Sligar, Stephen G (2002) Formation and decay of hydroperoxo-ferric heme complex in horseradish peroxidase studied by cryoradiolysis. J Biol Chem 277:42706-10
Atsarkin, V A; Demidov, V V; Vasneva, G A et al. (2001) Mechanism of oxygen response in carbon-based sensors. J Magn Reson 149:85-9
Mangels, M L; Harper, A C; Smirnov, A I et al. (2001) Investigating magnetically aligned phospholipid bilayers with EPR spectroscopy at 94 GHz. J Magn Reson 151:253-9
Breitzer, J G; Smirnov, A I; Szczepura, L F et al. (2001) Redox properties of C6S8(n-) and C3S5(n-) (n = 0, 1, 2): stable radicals and unusual structural properties for C-S-S-C bonds. Inorg Chem 40:1421-9
Denisov, I G; Hung, S C; Weiss, K E et al. (2001) Characterization of the oxygenated intermediate of the thermophilic cytochrome P450 CYP119. J Inorg Biochem 87:215-26
Kirkor, E S; Scheeline, A (2000) Nicotinamide adenine dinucleotide species in the horseradish peroxidase-oxidase oscillator. Eur J Biochem 267:5014-22
Rapoport, N; Smirnov, A I; Pitt, W G et al. (1999) Bioreduction of Tempone and spin-labeled gentamicin by gram-negative bacteria: kinetics and effect of ultrasound. Arch Biochem Biophys 362:233-41
Maringanti, S; Imlay, J A (1999) An intracellular iron chelator pleiotropically suppresses enzymatic and growth defects of superoxide dismutase-deficient Escherichia coli. J Bacteriol 181:3792-802

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