[Synthesis, conformation analysis, and antiviral activity of benzimidazole ribofuranosides]. / Sintez, konformatsionnyi analiz i izuchenie protivovirusnoi aktivnosti ribofuranozidov benzimidazola.

To study the structure-biological effect correlation in the series of nucleoside analogues containing deazapurines, a number of 2-R-benzimidazole 1-beta-D-ribofuranosides (R = H, CF3, SCF3, CH2SCF3, CH2Ph, CH2CN) have been prepared by the modified silyl method. On the basis of CD and PMR data it was shown that the compounds exist in solution mainly as syn-conformers. Calculation of the furanose ring pseudorotation parameters in terms of N-S model indicates the predominance of S-population. In contrast to acyclonucleosides, the ribofuranosides obtained are nonactive against entheroviruses and more cytotoxic.

[Citrate transport in submitochondrial particles of the rat liver]. / Transport tsitrata v submitokhondrial'nykh chastitsakh pecheni krys.

The submitochondrial particles (SMP, inverted inner membrane vesicles of mitochondria of the turned out vesicles in internal mitochondrial membranes) of the rat liver are characterized for their ability to incorporate [14C]citrate depending on the concentration of exogenic citrate, temperature and time of incubation. The rate of citrate incorporation into SMP does not depend on the addition of the oxidation substrate into the medium, however in the presence of malate and phosphate it is sharply activated. 1,2,3-benzene tricarboxylase (1,2,3-BTC) is an active inhibitor of the citrate transport into SMP. The citrate transport is determined by the protonation-deprotonation processes of the carrier protein on the outer and inner side of the membrane. A decrease in the pH of the medium favours protonation of the carrier protein on the outer side of the membrane and intensifies [14C]citrate incorporation into SMP, whereas the pH increase inhibits this process. The effect of pH changes is less pronounced in the presence of K+ ions. Valinomycin in the K+ medium activates incorporation of [14C]citrate increasing the carrier protein deprotonation rate on the inner side of the SMP membrane. Protonophore separators intensify conductivity for H+ ions and remove the stimulating influence of valinomycin on the rate of [14C]citrate incorporation into SMP.

[Physicochemical and immunochemical properties of submolecular structures of immunoglobulin G characteristic of cancer]. / Fiziko-khimicheskie i immunokhimicheskie svoistva submolekuliarnykh struktur immunoglobulina G, kharakternogo dlia raka.

Studies in physicochemical and immunochemical properties of polipeptide chains fragments of immunoglobulin G malignant growth permitted detecting the location site for a specific determinant which adds a unique feature to the whole molecule of immunoglobulin G. The specific antigenic determinant is defined by a group of amino acids located in the heavy chain site corresponding to Fd-fragment. During papain and trypsin hydrolysis of specific immunoglobulin G obtained from different patients the formed sets of fragments and peptides are different. This testifies to the fact that the immunoglobulin under study may belong to any of four subclasses of immunoglobulin G, that is confirmed by the immunochemical analysis with application of monospecific antisera against certain subclasses of immunoglobulin G.

[Physicochemical and immunochemical properties of heavy chains of immunoglobulin G typical of malignant growth]. / Fiziko-khimicheskie i immunokhimicheskie osobennosti tiazhelykh tsepei immunoglobulina G, kharakterno dlia zlokachestvennogo rosta.

Molecular weight of heavy chains of immunoglobulin G typical of cancer is studied immunoglobulin and may be responsible for manifestation of certain anomalous acid and peptide composition of this protein heavy chains as compared with immunoglobulin G in blood serum of healthy people. Immunochemical methods helped detecting an antigenic determinant (or determinants) which is arranged in the heavy chains of the studied immunoglobulin and may be responsible for manifestation of certain anomalous properties of cancer-typical immunoglobulin G molecules. A set of bromo-cyanogenic fragments differing from the spectrum of these fragments in the heavy chains of normal immunoglobulin G is formed following a specific chemical effect of bromo-cyanogen on the heavy chains of immunoglobulin G typical of cancer. Essential differences are found in dancyl-fingerprints of the heavy chains of the compared proteins. Everything mentioned is a result of changes in the primary structure of the heavy chains of immunoglobulin G typical of cancer.

[Electrofocusing of immunoglobulin G that reacts positively in the sedimentation reaction for cancer]. / Elektrofokusuvannia imunohlobulinu G, shcho pozytyvno reahuie v osadovii reaktsiï na rak

Immunoglobulin G from the serum of patients with myeloma and positively reacting in the sedimentary test for cancer (PPR-STC) was purified by DEAE-Spehadex A-50 and KM-cellulose chromotography and studied by the method of isoelectrofocusing; Application of 1% ampholine within the pH gradient 3.0-10.0 shows the difference between the isoelectric spectra of immunoglobulin G from the donor and from a patient with myeloma. The PPR-STC isoelectric point located in the zone of pH 8.4 is determined. No subfraction with pH 8.4 is observed in the fraction of the donor immunoglobulin G.

[Inhibition of the transport of citrate during ADP-ribosylation of inner membrane proteins of the mitochondria]. / Ingibirovanie transporta tsitrata pri ADP-ribozilirovanii belkov vnutrennikh membran mitokhondrii.

The ability of rat liver submitochondrial particles to catalyze NAD+ hydrolysis with a transfer of ADP-ribose residues to protein membranes has been demonstrated ADP-ribosylation is directly dependent on NAD+ concentration upon saturation with 1 mM NAD+ and is inhibited by physiological compounds (e.g., ATP, 10 mM; nicotinamide, 10 mM); besides, it is an artificial acceptor of ADP-ribose, arginine methyl ester. It was found that ADP-ribose is accepted by inner mitochondrial membrane protein, whose molecular masses amount to 25-30 kDa. The fact that 5'-AMP is a product of ADP-ribose degradation by snake venom phosphodiesterase suggests that the inner membrane vesiculate proteins are modified by mono(ADP-ribose). Covalent modification of membrane proteins by ADP-ribose leads to citrate transport inhibition in inner membrane vesicles the [14C]citrate uptake is significantly decreased thereby. The ability of ADP-ribosylation inhibitors to restore the citrate transport rate is suggestive of a direct regulatory effect of NAD+-dependent ADP-ribosylation on the activity of citrate-translocating system of inner mitochondrial membranes.