ABSTRACT
The role of mt-genome mutations in radiation-induced carcinogenesis has been hypothesized. The data on radiation chemistry of nucleic acids has been used to evaluate mutagenic effect of carcinogenic doses of ionizing radiation. The assumptions about the ways of biological augmentation of primary radiation-induced lesions in mt-genome has been given.
Subject(s)
Cell Transformation, Neoplastic , DNA Damage , DNA, Circular/radiation effects , Mitochondria/radiation effects , Mutation , Radiation, Ionizing , Adenosine Triphosphate/biosynthesis , Animals , Cattle , DNA, Circular/genetics , DNA, Circular/metabolism , Drosophila , Humans , Lipid Peroxidation , Liver/cytology , Liver/metabolism , Liver/radiation effects , Mice , Mitochondria/metabolism , Mitochondria, Liver/metabolism , Mitochondria, Liver/radiation effects , Models, Biological , Oxidative Phosphorylation , Radiation DosageABSTRACT
As was shown by the pulse radiolysis method the simultaneous presence of naphthoquinone and human serum albumin molecules in an aqueous solution leads to the adsorption of the former on the surface of the latter. It is suggested that in these conditions the protein tertiary structure changes. New conformation reduces the reactivity of albumin toward the hydrated electron.
Subject(s)
Naphthoquinones/pharmacology , Radiation-Protective Agents , Serum Albumin/radiation effects , Humans , Kinetics , Protein Conformation , SolutionsABSTRACT
The comparative changes in the amino acid composition of calf skin collagen after gamma-irradiation (doses from 100 to 1,000 Gy) in aqueous solutions under different gas atmospheres (O2, N2O, H2, vacuum) were investigated. The radiochemical yields of collagen amino acid residues destruction were determined. Under O2 (OH X, O2-) most of amino acids are destroyed with higher yields than under N2O. Leucine, valine, isoleucine, phenylalanine, arginine were the exception because of their high reaction rate constants with OH X and hydroxylation reactions. Under H2 (e-aq, H) and in vacuum (e-aq, OH X) the mechanism of collagen radiolysis changed due to its aggregation; the destruction of those amino acids which have high reaction rate constants with water radiolysis products was mainly observed (phenylalanine, tyrosine, histidine).
Subject(s)
Amino Acids/analysis , Collagen/radiation effects , Cobalt Radioisotopes , Collagen/analysis , Gamma Rays , Hydrogen , Nitrous Oxide , Oxygen , Solutions , Water/radiation effectsABSTRACT
An abnormality in the primary structure of dog haemoglobin was observed 1-20 days after their whole body irradiation with 190 keV X-rays (4.0 Gy). It consisted in a substitution of tryptophane residue in position 15 of the beta-chain for serine. The percentage of abnormal beta-chains in different time intervals after irradiation was determined. The structural changes have functional impact: an increasing haemoglobin affinity to oxygen. This could be explained on the basis of changes in the tertiary structure of haemoglobin, which may result from the substitution Trp 15----Ser15 in the beta-chain which may influence the haeme ability to bind oxygen.
Subject(s)
Hemoglobins/radiation effects , Amino Acids/analysis , Animals , Dogs , Globins/analysis , Globins/radiation effects , Hemoglobins/metabolism , Oxygen/metabolism , Peptides/analysis , Protein Conformation/radiation effects , Trypsin , Whole-Body IrradiationABSTRACT
A study was made of the amino acid composition of calf skin collagen after gamma-irradiation (60Co) of 2.5 X 10(-6) M aerated aqueous protein solution within the dose range from 30 to 2000 Gy. The radiosensitivity of amino acid residues was compared.
Subject(s)
Amino Acids/analysis , Collagen/analysis , Radiation Tolerance , Skin/radiation effects , Amino Acid Sequence/radiation effects , Animals , Cattle , Dose-Response Relationship, Radiation , Gamma Rays , In Vitro Techniques , Skin/analysis , SolutionsABSTRACT
Heterogeneity of dog hemoglobin is established with application of chromatographic analysis. Ionizing radiation (4 Grey) induces no changes in the ratio of hemoglobin components. The comparative dactylographical analysis of the hemoglobin components in norm and in different periods after irradiation revealed differences in responses to tryptophan in peptide T-25. The changes found are connected with disturbances in the structure of the DNA molecule as well as with modification of the protein molecule under conditions of radiation injury.
