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Biomedical subjects

G F Denisova

Publications and source records attributed to G F Denisova.

10 recordsLinked to original sources

[Aminooxypropylamine--an effective inhibitor of ornithine decarboxylase in vitro and in vivo].

Hydroxylamine-containing analogues of putrescine and cadaverine have been found effective in inhibiting the mouse liver ornithine decarboxylase, the best among synthesized were 1-aminooxy-3-aminopropane (I50 2.10(-8) M) and 1-aminooxy-4-aminobutane (I50 2.10(-7) M). The inhibitory effect of these substances on the mouse liver ornithine-transaminase and S-adenosylmethionine decarboxylase from E. coli was displayed at concentrations higher by several orders of magnitude, that demonstrated the specificity of the compounds of this type. 1-Aminooxy-3-aminopropane in experiments in vivo suppressed the ornithine decarboxylase activity in mouse liver at 16 mg/kg by 75%, the toxic effect being insignificant.

Animals

[A proteolytic enzyme bound to the aspartate transaminase of swine heart cytosol].

Purified preparations of aspartate transaminase from pig heart cytosol contain a tightly bound proteolytic enzyme (approximately 2, 5%). The enzyme was separated from aspartate transaminase by gel-filtration on Sephadex G-100 in the presence of sodium dodecyl sulfate and by affinity chromatography on the column with Sepharose, containing covalently bound denaturated aspartate transaminase. Protease has a pH optimum of 9.0 and molecular weight of about 23.000-25.000. The proteolysis rates of different subforms of aspartate transaminase depend on their denaturation lability. A more stable choloenzyme is split at a slower rate than the apoenzyme. An enriched preparation of protease was also shown to split glutamate decarboxylase from E. coli and had no effect on cysteinlyase from hen egg, as well as on lactate dehydrogenase and albumin.

Animals

[Native and artificial sub-forms of cytoplasmic aspartate transaminase from swine heart].

Multiple forms of aspartate transaminase from cytosol of pig heart (alpha, beta and psi) were incubated in 0.05 M acetate buffer, pH 5.0 at 4 degrees within 5 and 8 months. Gradual accumulation of denaturated forms was observed on incubation of alpha- and beta-forms; these forms possessed higher mobility in polyacrylamide gel disc electrophoresis and decreased enzymatic activity as compared with the native forms. Multiple forms, produced during ageing of alpha-form, were separated by chromatography on CM-cellulose. Chromatographic resolution of the forms, their activity and spectral properties suggest that they are not identical with the native isoenzymes found in the cell.

Animals

[The antigenic and immunogenic properties of a recombinant protein of the HIV-1 gag-pol gene secreted by Saccharomyces cerevisiae yeast cells].

Analysis of the immunological properties of recombinant proteins of HIV-1 gene gag-pol secreted by yeast cells S. cerevisiae was carried out. The proteins under study interacted with antibodies from HIV-1-seropositive human subjects and with antibodies of rabbit immune serum to the native virus as effectively and specifically as natural HIV-1 proteins. The yeast gag-pol-protein complex was markedly immunogenic and induced in animals synthesis of antibodies of a certain specificity spectrum. A comparative immunochemical analysis of the properties of the recombinant proteins carried out by EIA and immune blot showed a certain degree of similarity between the yeast proteins and those of analogous construction produced in E. coli system.

Animals

[Design of a recombinant strain of the vaccinia virus containing an expressible gene for influenza A virus hemagglutinin].

A recombinant vaccinia virus (VV) strain containing a cloned gene of influenza A/Udorn/307/72 (H3N2) hemagglutinin (HA) gene has been produced. HA expression in CV-1 cells infected with the recombinant virus was determined by enzyme immunoassay. The influenza virus HA titer was 1:64-1:128. When rabbits were inoculated intravenously with the recombinant VaV, antibody titres were 1:5120. The recombinant VaV preparation may be used for generation of monospecific antibody to influenza virus.

Animals

[Two variants of ornithine decarboxylase activity in the mouse liver. The nature of enzyme induction].

Ornithine decarboxylase activity in mouse liver is predominantly located in the cell nuclei. After injection of some inducing agents (thioacetamide, diethylnitrosamine, hydrocortisone) the enzyme leaves the nucleus for cytosol. A circadian rhythm of ornithine decarboxylase activity has been observed in nucleus and cytosol, the decrease of enzyme activity in the nucleus being accompanied by its increase in cytosol. The enzyme obtained from intact mice with a minimal level of ornithine decarboxylase activity in the cytosol differs in ion-exchange properties, pH-optimum and Km for ornithine from the thioacetamide stimulated (nucleus enzyme).

Animals