ESR studies of thiyl free radicals in relation to biological effects of radiation. Progress report

Technical Report · Sat Nov 01 04:00:00 EST 1975

OSTI ID:5187427

Wolf, W

Progress is reported on studies on the potential use of thiyl free radicals as conformational probes (internal spin labeling agents) in the study of polypeptides and proteins. A completed variable temperature assembly for flow studies allowed the reexamination of features of ESP signals over a range of specific temperatures, and the resultant line width and hyperfine coupling constant changes revealed a dependence suggesting that thiyl free radicals exhibit the phenomenon of alternating line width effects. Both cysteine and N-acetyl cysteine were reevaluated to determine the generality of this effect and were seen to exhibit various stages of interconversion from fast to intermediate exchange over the experimentally feasible temperature range. Dynamic information was extracted from an analysis of the temperature-dependent line shapes of the ESR spectra, by fitting experimental spectra to calculated spectra generated by a computer simulation program.

• Research Organization: University of Southern California, Los Angeles (USA)
• OSTI ID: 5187427
• Report Number(s): USC-113P21X9
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
CARBOXYLIC ACIDS
CYSTEINE
ELECTRON SPIN RESONANCE
GLUTATHIONE
MAGNETIC RESONANCE
MOLECULAR BIOLOGY
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDES
POLYPEPTIDES
PROTEINS
RADICALS
RESONANCE
STRUCTURAL CHEMICAL ANALYSIS
TEMPERATURE EFFECTS
THIOLS