Hydroxyl radical induced cross-linking of cytosine and tyrosine in nucleohistone

Journal Article · Tue Jan 30 04:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00456a020· OSTI ID:6696598

Gajewski, E; Dizdaroglu, M ^[1]

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1. National Institute of Standards and Technology, Gaithersburg, MD (USA)

Hydroxyl radical induced formation of a DNA-protein cross-link involving cytosine and tyrosine in nucleohistone in buffered aqueous solution is reported. The technique of gas chromatography-mass spectrometry was used for this investigation. A {gamma}-irradiated aqueous mixture of cytosine and tyrosine was first investigated in order to obtain gas chromatographic-mass spectrometric properties of possible cytosine-tyrosine cross-links. One cross-link was observed, and its structure was identified as the product from the formation of a covalent bond between carbon 6 of cytosine and carbon 3 of tyrosine. With the use of gas chromatography-mass spectrometry with selected-ion monitoring, this cytosine-tyrosine cross-link was identified in acidic hydrolysates of calf thymus nucleohistone {gamma}-irradiated in N{sub 2}O-saturated aqueous solution. The yield of this DNA-protein cross-link in nucleohistone was found to be a linear function of the radiation dose in the range of 100-500 Gy (J{center dot}kg{sup {minus}1}). This yield amounted to 0.05 nmol{center dot}J{sup {minus}1}. Mechanisms underlying the formation of the cytosine-tyrosine cross-link in nucleohistone were proposed to involve radical-radical and/or radical addition reactions of hydroxyl adduct radicals of cytosine and tyrosine moieties, forming a covalent bond between carbon 6 of cytosine and carbon 3 of tyrosine. When oxygen was present in irradiated solutions, no cytosine-tyrosine cross-links were observed.

• OSTI ID: 6696598
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:4; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ADDUCTS
AMINES
AMINO ACIDS
AQUEOUS SOLUTIONS
AZINES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHROMATOGRAPHY
COBALT 60
COBALT ISOTOPES
CROSS-LINKING
CYTOSINE
DISPERSIONS
DNA
DNA ADDUCTS
DOSE-RESPONSE RELATIONSHIPS
ELECTROMAGNETIC RADIATION
GAMMA RADIATION
GAS CHROMATOGRAPHY
HETEROCYCLIC COMPOUNDS
HISTONES
HYDROXY ACIDS
HYDROXYL RADICALS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MASS SPECTRA
MASS SPECTROSCOPY
MINUTES LIVING RADIOISOTOPES
MIXTURES
NUCLEI
NUCLEIC ACIDS
NUCLEOPROTEINS
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
POLYMERIZATION
PROTEINS
PYRIMIDINES
RADIATIONS
RADICALS
RADIOINDUCTION
RADIOISOTOPES
SEPARATION PROCESSES
SOLUTIONS
SPECTRA
SPECTROSCOPY
TYROSINE
YEARS LIVING RADIOISOT