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A N Nikolaenko

Publications and source records attributed to A N Nikolaenko.

12 recordsLinked to original sources
PubMed1996

Probing the structure-function relationship of alpha-latrotoxin-formed channels with antibodies and pronase.

The major toxic component of black widow spider (Latrodectus mactans tredecimguttatus) venom, alpha-latrotoxin, is known to form ionic channels in different membranes. In order to probe the extramembrane domains of alpha-latrotoxin molecule, alpha-latrotoxin channels in planar lipid membrane were treated with antibodies to latrotoxin or with pronase added to different sides of the membrane. It was found that antibody addition to the same side as the toxin (cis) decreased channel conductance only at positive potentials across the membrane. In contrast, trans side addition of antibodies changed the channel conductance at both positive and negative potentials: at positive potential conductance first slightly increased then decreased by more then 50%; at negative potential it decreased much more quickly, to only about 20% of the initial value. No dependence on membrane potential was found for pronase treatment of incorporated channels. For both cis and trans application of pronase, channel selectivity for Ca2+, Mg2+, Ba2+ and K+, Na+, Li+ ions did not change significantly but Cd2+ block was decreased. Trans pronase treatment also resulted in some rectification of I/V curves and an increase in channel conductance. We interpret these findings as evidence that alpha-latrotoxin channel has protruding parts on both sides of the membrane and that its conformation in the membrane depends on membrane potential.

Animals↗
PubMed1987

[Common features of the antigenic determinants presented on the membranes of mammalian nervous system cells and cytoplasmic tetrodotoxin-sensitive proteins].

Hypothetical antigenic similarities between nerve cell membrane structures and cytoplasmic tetrodotoxin-sensitive proteins have been studied. Indirect ELISA binding assay combined with inhibition assay has been used. The results obtained indicate that cytoplasmic tetrodotoxin-sensitive proteins do share antigenic determinants with nerve cell membrane structures. This is consistent with the speculation that cytoplasmic tetrodotoxin-sensitive proteins are relatives of membrane sodium channels.

Animals↗
PubMedDate not supplied

[Use of erbisol in chronic pancreatitis, depending on treatment options and concurrent ischemic heart disease in old and senile persons].

In old and senile persons, chronic pancreatitis is known to be accompanied by an uncontrolled intensification of process of free-radical lipid oxidation and inhibition of mechanisms of antiradical defence. The use of erbisol in the instituted therapeutic complex has been found to raise the efficiency of the system of glutathione and glutathione-dependent enzymes, to effect the inhibition of process of free-radical oxidation, improvement of conditions under which the synthesis of reduced glutathione is normally seen to proceed, realization of antiperoxide, disulphide reductase- and ribonucleotide reductase functions of the system as a whole. Moreover, there gets improved the incretory and exacrinous functions of the pancreas.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Analysis of hepatocyte cell membrane antigens in regenerating rat liver].

Antigens of plasma membranes in hepatocytes from regenerating rat liver were studied. Immunochemical investigation with polyvalent rabbits antiserum against plasma membrane proteins in hepatocytes from regenerating and normal rat liver have shown that liver regeneration processes are accompanied by the increase of proteins number with molecular weight of--80 kDa, 62 kDa, 40 kDa and 27 kDa. It is not excluded that protein with molecular weight of 27 kDa is the tissue-specific peripheral protein. The influence of antibodies against proteins of hepatocytes plasmatic membranes on histostructure of pathologically changed liver tissue has been studied. The data obtained testify to a possibility of participation of the above mentioned proteins in the regulation of rat liver regeneration processes.

Animals↗
PubMedDate not supplied

[A simple method of protein determination in polyacrylamide gel using silver staining].

A simple and relatively rapid method is elaborated for development of electrophoregram in PAAG by silver binding directly with protein. This permits avoiding the gel staining, considerably improves the quality of staining and promotes better reproducibility of the results. Sensitivity of the method permits detecting 1 ng of protein in the band.

Electrophoresis, Polyacrylamide Gel↗
PubMedDate not supplied

[Modification of latrotoxin channels under the effect of pronase and antibodies to latrotoxin].

The action of pronase and latrotoxin antibodies on alpha-latrotoxin channels in lipid bilayers has been investigated. Proteolysis of the protruding portions of the inserted channels changed slightly its conductivity and selectivity. Latrotoxin antibodies added to either side of the membrane decreased channel conductivity. The effect depends on the membrane potential. It is suggested that the channel conformation depends on the transmembrane potential and selective centre localized in the inner region of a bilayer is insensitive to proteolysis of protruding segments.

Antibodies↗
PubMedDate not supplied

[Isolation of alpha-latrotoxin using high-performance liquid chromatography methods].

alpha-Latrotoxin, a main toxic component of the Latrodectus mactans tredecimguttatus venom is a large polypeptide with molecular weight of 130 KDa. A rapid method is suggested for isolating this protein using high-effective liquid chromatography on chromatograph FPLC ("Pharmacia", Sweden). The isolated protein does not differ from the previously described alpha-latrotoxin in the main physicochemical parameters as well as in physiological properties.

Animals↗
PubMedDate not supplied

[Physico-chemical properties of IgG characteristic for normal growth].

It is shown that IgG typical of the normal growth appears in blood of rats with the regenerating liver and in pregnant ones and its capacity to form complexes with alpha-globulins insoluble in acid medium, isoelectric point and molecular mass are similar to these features in IgG typical of the malignant growth. At the same time hydrophobic properties and energy stability of this protein are close to those of IgG in control animals. The accessibility of ionogenic groups for titration in the studied protein varies like that observed in IgG typical of the malignant growth but is less pronounced. The data obtained evidence for the fact that subpopulations of IgG molecules with similar but not identical properties appear in blood of animals with the normal and malignant growth.

Animals↗
PubMedDate not supplied

[Isolation of immunoglobulin G--marker of normal growth in the blood of the rat].

The blood of rats with a regenerating liver and of pregnant animals is found to contain a peculiar subfraction of immunoglobulin G (IgG) which is absent in the blood of control animals. A characteristic feature of the protein which permits its detection among other proteins of this class, is its ability to form a complex with serum alpha-globulins insoluble in the acid medium. The complex in composition and conditions of formation differs from that formed by IgG typical of malignant growth. This shows that in blood of animals with normal and malignant growth there appears a subfraction of IgG with similar properties but not identical to it. Isolation of the studied IgG from the formed complex insoluble in the acid medium is suggested as a preparative method for obtaining its subpopulation.

Animals↗
PubMedDate not supplied

[An evaluation of the efficacy of the new Ukrainian preparation Erbisol in patients with chronic hepatitis].

A new drug preparation "Erbisol" was studied for its effect in the treatment of chronic hepatitis. There were 52 patients; of these, chronic active hepatitis was diagnosed in ten, persistent hepatitis in 38, cholangiolytic hepatitis in 4 patients. The preparation has a beneficial effect on the clinical course of the disease and makes for the normalization of biochemical and immunological indicators in patients with persistent hepatitis and in those with chronic active hepatitis with mild degree of activity. In patients with cholangiolytic hepatitis "Erbisol" should be used with caution. The studies made allowed for the conclusion to be drawn to the effect that the preparation "Erbisol" is a highly effective hepatoprotective and immunomodulating drug.

Adjuvants, Immunologic↗