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T V Popova

Publications and source records attributed to T V Popova.

16 recordsLinked to original sources
PubMed2004

Photoanalogues of the initiation substrates of the RNA polymerase II, 5-azido-2-nitrobenzoyl derivatives of the ATP gamma-amidophosphate: the possible photoinduced degradation of the functional group to an N-arylhydroxylamine.

Photoanlogues of the initiation substrates of the RNA polymerase II, N3ArNH(CH2)(n)NHpppA where N3Ar is 5-azido-2-nitrobenzoyl group (n = 2 or 4) were synthesized, allowing the preparation of photoreactive oligonucleotides in situ by RNA polymerase II for application as photolabels. Photolysis of p-nitro-substituted aromatic azide in aqueous medium was investigated. Using the azoxy-coupling reaction it was possible to determine whether a nitrene or p-nitrophenyl hydroxylamine azoxy compound is the trappable intermediate that is generated at ambient temperature in aqueous solution.

Adenosine Triphosphate↗
PubMed2001

Long-lived reactive intermediate photogenerated from N-(5-azido-2-nitrobenzoyl)-N'-(D-biotinyl)-1,2-diaminoethane as an affinity reagent to streptavidin.

Irradiation of a complex between N-(5-azido-2-nitrobenzoyl)-N'-(D-biotinyl)-1,2-diaminoethane (I) and streptavidin with light of 313 nm led to the covalent attachment of the photobiotin analogue I to the protein. Streptavidin could also be labelled in the dark with prephotolyzed I. These results indicate that a long-lived reactive intermediate was formed upon irradiation. Moreover, after cleavage of labelled streptavidin with proteinase K this intermediate appears to be covalently attached to the same peptide as the one obtained by direct photoaffinity labelling. An iminosulfurane II derived from the reaction of biotin sulfur atom with aryl nitrene is responsible for the dark-labelling reaction. The photoproduct II converts in an aqueous solution almost completely into N-(5-amino-2-nitrobenzoyl)-N'-(D-(S-oxo)biotinyl)-1,2-diaminoethane (the half-life of II is 10 days).

Biotin↗
PubMed1999

[Role of heat-shock proteins in cardioprotection of patients operated on for ischemic heart disease].

Major stress protein HSP72 is known to participate in protecting cells and organisms against harmful factors including ischemia, trauma etc. Under study was the level of HSP72 in the myocardium of 32 patients with coronary disease operated in Military-medical academy. HSP72 was detected in probes of the right atria before and after pre-cardiopulmonary bypass in all cases induction of HSP72 was observed in 40% of patients, and directly correlated with the time of cardiopulmonary bypass and standing of the disease. The cardioprotective effect of the elevated pre-operational level of HSP72 was shown to be proportionate to the lower activity of cardiospecific enzymes, creatine phosphokinase (CK-MB). It is suggested that HSP72 is involved in the mechanism of cardioprotection during cardiopulmonary bypass.

Adult↗
PubMed1990

[Clinico-hysteroscopic characteristics of chronic endometritis].

Clinical presentations of chronic endometritis have been compared with hysteroscopic findings in 60 women of reproductive age. Clinical and hysteroscopic data were indicative of a close correlation of gross endometrial abnormalities with certain symptoms of chronic endometritis and of severity and pattern of mucosal lesions of the corpus mucosa. Elucidation of clinical and hysteroscopic features of chronic endometritis permits a differential approach to the management of these patients.

Adult↗
PubMed1990

[Immunoglobulin levels in endometrial secretion in patients with chronic endometritis].

Immunoglobulin levels have been assayed in endometrial secretions from 30 patients with chronic, 25 patients with acute endometritis and 15 normal women. Concentrations of IgG, IgA and, especially, IgM were high in patients with chronic endometritis as compared with the normal women and patients with acute endometritis. These findings suggest that immunoglobulin studies may be used as a diagnostic and predictive test.

Adult↗
PubMed1989

[Echomorphological comparisons in chronic diseases of the liver].

Altogether 139 patients with liver diseases were examined by ultrasonography. Of these, 42 patients suffered from liver cirrhosis, 27 from chronic active hepatitis, 62 from chronic persistent hepatitis, and 8 from liver steatosis. The ultrasonography data were compared with the data of the morphological study of liver biopsy specimens and with the level of hydroxyprolinemia as a characteristic of the development of the connective tissue in the liver. It was established that pronounced acoustic heterogeneity of liver tissue was typical for liver cirrhosis and fatty dystrophy of the liver and that the distinctive sign of liver cirrhosis might be poor visibility of the posterior contour of the liver. In chronic active hepatitis, the focal structures in the portal fissure were detectable in 50 percent of the cases. In chronic persistent hepatitis, the liver appeared acoustically homogeneous. It is concluded that the connective tissue, fatty infiltration of hepatocytes, and round-cell inflammatory infiltration of the liver tissue that is pronounced as to the spreading and intensity may be an object of visualization during ultrasonography.

Biopsy, Needle↗
PubMedDate not supplied

[Photoactivated analogues of the initiating substrates of RNA polymerase II based on arylazide derivatives of NTP gamma-amidophosphate: synthesis and chemical and photochemical reactions of functional groups].

Photoactivatable derivatives Ar-NH-(CH2)n-NHpppB (where Ar = p-azidophenyl (A1), 5-azido-2-nitrobenzoyl (A2), or 4-azido-2,3,5,6-tetrafluorobenzoyl (A3) group; B = Ado or Guo; n = 2, 3, or 4) were synthesized. The phosphoroamidate bond stability was found to depend on the structure of both the heterocyclic and the photoactivatable groups. The derivative with A3, Ado, and n=3 is hydrolyzed with regeneration of aryl azide and ATP, whereas the other derivatives are stable in aqueous solutions. The photoanalogues with A1 and A2, B = Ado, and n = 2 or 4 were found to behave as initiating substrates toward the RNA polymerase II from Saccharomyces cerevisiae under the conditions of specific transcription initiation and control of the adenovirus late promoter. The photolysis of N-(4-azidophenyl)-1,4-diaminobutane and N-(5-azido-2-nitrobenzoyl)-1,3-diaminopropane, two functional fragments of the photoaffinity reagents, in aqueous solutions was established to result in the formation of p-benzoquinone diimine and p-nitro-N-arylhydroxylamine derivatives, respectively. The arylhydroxylamine derivatives undergo a number of transformations in aqueous solution leading to nitroso derivatives. We concluded that it is these nitroso derivatives (products of nitrene transformation, rather than the nitrene itself) that may modify proteins with reagents containing p-nitrophenylazide fragment.

Adenosine Triphosphate↗
PubMedDate not supplied

[Coronary-active bovine heart proteins induce relaxation in the rabbit aorta].

Seven cardioactive polypeptides have been identified in the precardiac and auricular regions of the bovine heart. Those polypeptides were studied for their action on the function of isolated preparations of the vessel. It has been found that compounds isolated from the precardiac region induce different (20-55%) relaxation of smooth muscles in a strip of the aorta of rabbit. The possibility of formation of endogenic cardioactive compounds in model experiments imitating processing is studied. The data obtained permit assuming and alternatively explaining existence of multiple forms of the mentioned compounds as a result of partial proteolytic splitting of larger molecules.

Animals↗
PubMedDate not supplied

[Detection and identification of new cardioactive proteins in cattle heart].

Seven cardioactive polypeptides were identified in precardiac and auricular regions of bovine heart. Procedures used for purification of the polypeptides involved extraction of water-soluble proteins, fractionation by ammonium sulfate, gel filtration on Sephadex G-100, chromatography and rechromatography on DEAE cellulose. Some physico-chemical and biological properties were studied; amino acid composition, N-terminal amino acids, molecular mass and the effects on coronary blood vessels. The data obtained suggest that multiple forms of these proteins may exist either as a result of partial hydrolysis of large molecules or due to processing of precursors.

Amino Acids↗