title: [The possible role of the elements of protein secondary structure in adaptation to the action of ionizing radiation].
abstract: Changes in the secondary structure of enzymes induced by gamma-rays 60Co at doses not exceeding one ionization per macromolecule were studied to elucidate a possible role of radiation-chemical processes in the evolution of proteins. The data on the comparative radioresistance of various types of secondary protein structures, alpha-helix, parallel and anti-parallel beta-structures, and beta-turn, were obtained by the method of circular dichroism. It was shown that beta-turns were resistant against radiation, alpha-helix was relatively stable, and beta-layer underwent significant changes. The importance of these structural types in the evolution of proteins is discussed. A special role of beta-turn as structural elements fixing the confirmation of macromolecules and therefore responsible for adaptation of the protein structure against a constant radiation background is proposed.
authors.forename: L I
authors.initials: LI
authors.lastname: Kharchenko
authors.forename: T E
authors.initials: TE
authors.lastname: Pavlovskaia
mesh_terms: D000222:Adaptation, Physiological / Q000528:radiation effects*; D000426:Alcohol Dehydrogenase / Q000528:radiation effects*; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D006736:Horses; D007770:L-Lactate Dehydrogenase / Q000528:radiation effects*; D008099:Liver / Q000201:enzymology; D009132:Muscles / Q000201:enzymology; D010179:Pancreas / Q000201:enzymology; D017433:Protein Structure, Secondary / Q000528:radiation effects*; D012260:Ribonucleases / Q000528:radiation effects*; D013381:Subtilisins / Q000528:radiation effects*; D013552:Swine
chemical_list: D000426:Alcohol Dehydrogenase; D007770:L-Lactate Dehydrogenase; D012260:Ribonucleases; D013381:Subtilisins