[The effect of chronic x-ray radiation at low doses on the gamma-glutamyl transpeptidase activity in rat organs and tissues]. / Vliianie khronicheskogo rentgenovskogo izlucheniia v malykh dozakh na aktivnost' gamma-glutamiltranspeptidazy v organakh i tkaniakh krys.

Effect of chronic low dose X-ray irradiation (total doses of 2.58, 5.16, 6.46, 7.75, 10.32 and 12.92 mC/kg) on gamma-glytamyltranspeptidase activity was investigated in rat organs and tissues which were different by radiosensitivity. Enzymatic activity was measured one hour after exposure. The increase in enzymatic activity was found in brain, liver, lungs, spleen, blood serum and partially in kidneys under all exposure doses. Exposure to 2.58, 5.16 and 12.92 mC/kg inhibited gamma-glutamyltranspeptidase activity in small intestines.

[The glutathione content and glutathione-S-transferase activity in the organs and blood of rats following chronic irradiation at low doses]. / Soderzhanie glutationa i aktivnost' glutation-S-transferazy v organakh i krovi krys posle khronicheskogo oblucheniia v malykh dozakh.

The effect of chronic low dose-rate irradiation with X-rays up to total doses of 2.58, 5.16, 6.46, 7.75, 10.32, 12.92 mC/kg on glutathione content and glutathione-S-transferase activity in Wistar rats organs, different by radiosensitivity, was studied 1 h after exposure. It has been shown that level of oxidized and reduced glutathione forms was not changed after exposure to 2.58 mC/kg, was enhanced in kidney and brain tissues after exposure to 5.16 and 6.46 mC/kg and was decreased in brain, lungs, small intestines and blood serum after ray exposures to higher doses. Inhibition of glutathione-S-transferase activity was found in liver, kidneys and spleen.

[The effect of x-ray radiation and hypoxia on the proteolytic activity of the normal rat spleen and during tumor growth]. / Vliianie rentgenovskogo izlucheniia i gipoksii na proteoliticheskuiu aktivnost' selezenki krys v norme i pri opukholevom roste.

The influence of X-radiation on activity of lysosomal enzymes (D, L, H cathepsins) in rat spleen tissue and in inoculated rat sarcoma 45 has been investigated. Intact rats and rats with tumors were subjected to whole-body and sarcoma 45 to local irradiation with doses of 0.155 C/kg and 0.31 C/kg in conditions of breathing gas hypoxic mixture containing 90% of nitrogen and 10% of oxygen (GHM-10). The combined exposure to radiation and GHM-10 was shown to produce a certain protective action (e.g. normalized cathepsin activity) in the spleen. In the tumor tissue the protective effect of GHM-10 was absent.

[An increase in the brain homocarnosine level during alcohol intoxication]. / Uvelichenie soderzhaniia gomokarnozina mozga pri alkogol'noi intoksikatsii.

It is shown that the content of neurospecific dipeptide of homocarnosine in the brain and blood of rats increases considerably after intraperitoneal administration of ethanol. The exogenous leu-enkephalin exerts an effects on the development of the alcoholic organism response.

[Cathepsin H activity in the human brain and human brain neoplasms]. / Aktivnost' katepsina H v mozge i opukholiakh mozga cheloveka.

The human brain cathepsin H is shown to be a specific cysteine aminopeptidase with the optimum activity at pH 6.0. Human brain tumours of neuroectodermal (astrocytomas and glioblastomas) and epithelial (meningiomas) origin were used to study the cathepsin H activity in the malignant brain tissue. A significant increase in the aminopeptidase cathepsin H activity was found in malignant human brain tumours as compared to benign tumours and normal brain tissues.

[Ammonia content of the brain, liver and blood of rats in radiation injury]. / Soderzhanie ammiaka v golovnom mozge, pecheni i krovi krys pri luchevom porazhenii.

The neuroparalytic syndrome induced by ammonia was compared with the X-radiation-induced cerebral syndrome. It is suggested that the accumulation of ammonia in the brain and liver of rats is one of the reasons for the similarity of the studied syndromes. The fact that ammonia is bound by glutamic acid indicates that the latter is involved in the mechanisms of ammonia utilization and in the radioprotective properties manifestation.

[Characteristics of various nerve tissue proteins using group-specific sorbents]. / Kharakteristika nekotorykh belkov nervnoi tkani s primeneniem gruppospetsifichnykh sorbentov.

The use of micro-scale column chromatography and affinity immunoelectrophoresis with group-specific sorbents allows studying some physical and chemical properties of protein molecules. A comparison of properties of soluble and membrane brain amino-peptidases carried out by means of micro-scale phenyl-sepharose and ConA-sepharose column chromatography shows that the membrane-bound aminopeptidase is a glycoprotein which possesses a high capacity to hydrophobic interactions. Soluble forms of aminopeptidase do not interact with ConA or phenyl residues. The crossed affinity immunoelectrophoresis in the presence of phenyl-sepharose also shows the presence of hydrophobic domains on the surface of glial fibrillary acidic protein molecules. The both approaches may be useful to predict conditions for large-scale affinity chromatography methods of protein and enzyme purification.

[Immunochemical study of the degradation of circulating glycoproteins and the neurospecific membrane glycoprotein D2 by cathepsin D of the human brain]. / Immunokhimicheskoe izuchenie degradatsii syvorotochnykh glikoproteinov i neirospetsificheskogo membrannogo glikoproteina D2 katepsinom D iz mozga cheloveka.

Cathepsin D was isolated from human brain. A consecutive use of affinity chromatography on hemoglobin-sepharose 4B and column chromatography on hydroxylapatite resulted in a homogeneous enzyme (as was demonstrated by SDS polyacrylamide gel electrophoresis) with a molecular weight of about 48,000, 2800-fold purification and 3.4% yield. Incubation of serum proteins in the presence of purified cathepsin D resulted in a gradual decrease of immunoreactive forms of albumin, orosomucoid, transferrin, and other alpha 1, alpha 2 and beta-globulins. The degradation was revealed by crossed immunoelectrophoresis. Crossed affinity immunoelectrophoresis in the presence of ConA showed specific degradation of serum glycoproteins. Rocket immunoelectrophoresis with monospecific antisera raised against human adult brain glycoprotein D2 revealed a rapid and linear degradation of detergent-solubilized and partially purified human membrane glycoprotein D2 by purified cathepsin D. Incubation of glycoprotein D2 in the presence of cathepsin D (30 min, 37 degrees C) resulted in degradation of 95% of specific protein. An exposure of human brain membrane fragments to cathepsin D resulted in linear degradation of membrane-bound glycoprotein followed by an appearance of a soluble immunoreactive form of protein D2.

[Effect of hypothermia on subcellular distribution and various physico-chemical properties of cathepsin D in rat brain]. / Vliianie gipotermii na subkletochnoe raspredelenie i nekotorye fiziko-khimicheskie svoistva katepsina D v golovnom mozgu krys.

The total cooling ef rats down to the rectal temperature 30 degrees and 20 degrees C does not change significantly the ratio of the relative specific activity of cathepsin D in subcellular fractions of the rat brain. The gel chromatographic analysis of heterogeneity of cathepsin D molecular forms in subcellular fractions established the presence of a high-molecular (in the fractions of lysosome and microsome mitochondria) and a low-molecular (in the fractions of lysosome and cytosol mitochondria) enzyme forms. Under hypothermia (20 degrees C) in the brain cytosol fraction there arises a minor zone of the cathepsin D activity corresponding to the high-molecular enzyme form.

[Glycyl-glycine dipeptidase from cat nervous tissue]. / Glitsilglitsin-dipeptidaza nervnoi tkani koshek.

The local distribution of glycyl-glycine dipeptidase (EC 3.4.13.1) from cat nervous tissue was studied. Using disc-electrophoresis, the multiplicity of the enzyme molecular forms was demonstrated. Glycyl-glycine dipeptidase from water extract and the partially purified enzyme forms revealed three similar or identical values of the pH optimum. The curves for the dependence of the reaction rate versus substrate concentrations for all the three enzyme forms under study are S-shaped. The kinetic data and the values of the Hill coefficient calculated by different methods are suggestive of allosteric properties of the cat brain enzyme.

[Purification and properties of thiol-activated cathepsin from bovine cerebrum and cerebellum]. / Ochistka i nekotorye svoistva tiolaktiviruemogo katepsina iz bol'shikh polusharyi golovnogo mozga i mozzhechka byka.

Thiol-activated cathepsin was isolated from bovine cerebral hemispheres and cerebellum. The enzyme from the hemispheres was purified by the affinity sorbent chromatography method with the sepharose-4B-immobilized protein substrate, azocasein, and with subsequent separation of nonspecifically sorbed protein by column gel-chromatography on Sephadex G-100. The cathepsin pH-optimum was 6.0. The coincidence in cellular (neuron and glia enriched fractions) and subcellular distribution of cathepsin D and thiol-activated cathepsin activities shows the probable lysosomal origin of the latter. The data obtained about the influence of the various proteolytic enzyme inhibitors and activators on the thiol-activated cathepsin activity show a definite similarity of the enzyme with the thiol proteinases of the rat liver lysosomes, cathepsin B1 and L.

[Purification and properties of inhibitor from vegetative portion of alfalfa]. / Ochistka i nekotorye svoistva ingibitora tripsina iz vegetativnykh organov liutserny.

Trypsin inhibitor was isolated from the vegetative portion of alfalfa and purified 270-fold by affinity chromatography on Trypsin-Sepharose. The inhibitor was eluted by gel-filtration as a single peak with molecular weight of 6900. Disc-electrophoresis of the purified inhibitor revealed the presence of only one protein band. Trypsin inhibition is a mixed process. The trypsin inhibitor from alfalfa does not prevent the activity of cathepsin D from bovine brain. Trypsin inhibitor was immobilized on BrCN-activated Sepharose 4B. The binding of trypsin to the immobilized trypsin inhibitor was studied: 5 mg of the immobilized trypsin inhibitor were found to bind 1 mg of trypsin.

[Catalytic properties of cathepsin D from the brains of normal and irradiated animals]. / Kataliticheskie svoistva katepsina D iz mozga normal'nykh i obluchennykh zhivotnykh.

Biospecific sorbent, hemoglobin-biogel P-300, was used for purification of cathepsin D from the brain and spleen of a cat and from the brain of normal and irradiated rats. 800 R irradiation of rats in 7 days causes changes in the catalytic properties of cathepsin D: shift of the pH-optimum of the activity, increase in the enzyme affinity to the substrate (hemoglobin) and inhibitor (pepstatin), changes in the activation energy. These changes may be due to the destruction of the processes of posttranscriptional modification of the enzymes at the late stage of the radiation pathology. The temperature dependence of the enzyme reaction catalyzed by cathepsin D from different tissues expressed in the Arrhenius coordinates is characterized by changes in the activation energy in the high-temperature region beginning with the critical temperature (26-30 degrees C). The results obtained may be explained by the presence of cathepsin E admixtures in the purified cathepsin D preparation (in spleen) or by the presence of cathepsin D isoforms catalyzing hemoglobin hydrolysis with different activation energy.

[Isolation and purification of bovine and porcine cerebral cathepsin D]. / Vydelenie i ochistka katepsina D iz kory golovnogo mozga byka i svin'i.

Cathepsin D was isolated from the grey matter of bovine and porcine large cerebral hemispheres and purified by affinity chromatography on haemoglobin--Sepharose. The isolation and purification of the enzyme also included: acidic extraction, precipitation by ammonium sulfate, dialysis, affinity chromatography, concentration and gel-chromatography on Sephadex G-100. The degree of purification of bovine cerebral enzyme was 3280. The Km value for the enzyme was 2,06 . 10(-5) M. The purified enzyme from bovine brain showed three major and two minor adjacent bands, possessing the cathepsin D activities. The purified enzyme from porcine brain showed only one protein band.

[Cathepsin B1 activity in cat brain tissue]. / Issledovanie aktinvnosti Katepsina B1 tkani golovnogo mozga koshek.

The dependence of the cathepsin B1 (EC 3.4.22.1) activity on pH of a medium with substrates N alpha-benzoyl-L-arginine amide (BAA) and N alpha-benzoyl-DL-arginine-paranitroanilide (BAPNA) was studied. Several maxima of the studied enzyme activity are established depending on pH in the grey and white matter of the cat cerebral hemispheres. The activity of cathepsin BI is different in functionally and morphologically different areas of brain (grey matter of cerebral hemispheres less than than cerebellum less than white matter of cerebral hemispheres less than medulla oblongata). A six-fold freezing and defrosting of homogenates of the brain structures under study causes an increase in the cathepsin B1 activity. It is shown that the cathepsin B1 activity in the brain grey matter grows in the presence of L-cysteine and is inhibited under the effect of pChMB, monoiodoacetic acid, Mn2+ and Cu2+.

[Molecular forms of acid proteinases of the brain]. / Molekulairnye formy kislykh proteinaz mozga

Molecular forms of cathepsin D bound with subcellular structures were studied in the grey matter of the large hemispheres. Free and bound forms of the enzymes exposed to solubilization with detergent triton X-100 were fractionated by passage through a Sephadex G-100 column. Gel chromatographic analysis demonstrated three peaks of acid proteinase activity. Different areas of solubilization curves of acid proteinases corresponded to different molecular forms of cathepsins. The initial S-shape areas of solubilization curve corresponded to the first high molecular weight peak of the enzyme activity in the grey matter, whereas the subsequent linear ones -- to the second peak; the activity of free forms of the enzyme corresponded to the third peak.