ESR and ENDOR study of 5'dCMP at 6 K

Journal Article · Mon Jan 01 04:00:00 EST 1979 · J. Chem. Phys.; (United States)

OSTI ID:6600619

Close, D M; Bernhard, W A

The ESR spectra of single crystals of deoxycytidine 5'-phosphatexH/sub 2/O (5'dCMP), x irradiated at 11 K and observed at 6 K, exhibit signals from three distinct free radicals. Analysis of the ENDOR spectra from two of these radicals indicates that these result from oxidation and reduction of the cytosine base. The reduced species exhibits hyperfine coupling to the C/sub 6/--H/sub b/ proton (A/sub iso/(H/sub 6/) =-1.392 mT). The oxidized species exhibits hyperfine couplings to the C/sub 5/--H/sub b/ proton (A/sub iso/(H/sub 5/) =-1.495 mT), N/sub 1/ and N/sub 3/, (A/sub iso/(N/sub 1/) approx.0.5 mT), (A/sub iso/(N/sub 3/) approx.0.25 mT) and to the C/sub 1/'--H/sub ..beta../ proton (A/sub iso/(H/sub ..beta../) =1.483 mT). The third free radical has ESR spectra characteristic of an oxygen centered defect and is thought to be a hole located primarily on the C/sub 3prime/--O/sub 3prime/ oxygen, but shared with a neighboring HO--PO/sup -//sub 3/-CH/sub 2/- group.

• Research Organization: Department of Radiation Biology and Biophysics, School of Medicine and Dentistry, The University of Rochester, Rochester, New York 14642
• OSTI ID: 6600619
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 70:1; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
ENDOR
IONIZING RADIATIONS
MAGNETIC RESONANCE
NUCLEIC ACIDS
ORGANIC COMPOUNDS
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOLYSIS
RESONANCE
ULTRALOW TEMPERATURE
X RADIATION