[Radiation-induced damage of mitochondrial genome and its role in long-term effects of irradiation]. / Radiotsionnoe povrezhdenie genoma mitokhodrii i ego rol' v otdalennykh posledstviiakh oblucheniia.

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.

[Pulsed radiolysis of aqueous solutions of serum albumin containing naphthoquinones]. / Impul'snyi radioliz vodnykh rastvorov syvorotochnogo al'bumina, soderzhashchikh naftokhinony.

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.

[Characteristics of the effect of gamma-irradiation on the amino acid composition of collagen as modified by a gaseous atmosphere]. / Ob osobennostiakh deistviia gamma-izlucheniia na aminokislotnyi sostav kollagena pri modifitsiruiushchem vliianii gazovoi atmosfery.

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).

Radiation induced structural and functional modification of haemoglobin.

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.

[Changes in the collagen amino acid composition of calf skin after gamma-irradiation in an aqueous solution]. / Izmenenie aminokislotnogo sostava kollagena kozhi telenka pri gamma-obluchenii v vodnom rastvore.

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.

[Structural anomalies of dog hemoglobin after ionizing irradiation]. / Strukturnye anomalii gemoglobina sobak pri vosdeistvii ioniziruiushchikh izluchenii.

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.