title: Radiation damage to histone H2A by the primary aqueous radicals.
abstract: Histone H2A has been examined for radiation-induced changes in structure and in amino acid composition. The effects of the individual radical intermediates--the hydroxyl radical, solvated electron, and superoxide radical--have been determined by irradiating in dilute aqueous solution under controlled environmental conditions. Amino acid analysis of irradiated histone H2A shows a selective attack on a few residues; only the aromatic residues, phenylalanine and tyrosine, and the heterocyclic residue, histidine, are significantly decreased. A significant increase in aspartic acid is also observed. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis shows that the hydroxyl radical is the effective radical for promoting changes in protein structure.
mesh_terms: D000596:Amino Acids / Q000528:radiation effects; D004583:Electrons; D004591:Electrophoresis, Polyacrylamide Gel; D005609:Free Radicals; D006657:Histones / Q000528:radiation effects*; D011487:Protein Conformation / Q000528:radiation effects; D013481:Superoxides / Q000494:pharmacology; D014867:Water / Q000528:radiation effects
chemical_list: D000596:Amino Acids; D005609:Free Radicals; D006657:Histones; D014867:Water; D013481:Superoxides