[Enzymatic transglycosylation of natural and modified nucleosides by immobilized thermostable nucleoside phosphorylases from Geobacillus stearothermophilus].

Natural and modified purine nucleosides have been synthesized using the recombinant thermostable enzymes purine nucleoside phosphorylase II (EC 2.4.2.

[Synthesis of 2-chloro-2'-deoxyadenosine by microbiological transglycosylation using a recombinant Escherichia coli strain].

Cladribine (2-chloro-2'-deoxyadenosine) was synthesized using intact cells of the recombinant Escherichia coli strain producing Geobacillus stearothermophilus B-2194 thermostable purine-nucleoside phosphorylase II (EC 2.4.2.

[Biotechnological synthesis of ribavirin. Effect of ribavirin and its various combinations on the reproduction of Vaccinia virus].

The biotechnological method of synthesis of ribavirin, vidarabin, and 6-azauridine by the use of immobilized recombinant enzymatic preparations of nucleoside phosphorylase was improved. The effect of ribavirin and its combinations with the other synthesized nucleosides on the reproduction of Vaccinia virus was studied using cultures of Vero cells. The combination of ribavirin and vidarabin was shown to provide an antiviral effect at lesser concentrations than when these compounds were taken separately.

[Design of an expression vector for delivery of in vivo recombinant biologically active proteins. 1. Synthesis of the antigenic determinant of HIV-1 gp120 and gp41 proteins in enterobacteria].

High-level expression vector pAZ was constructed for in vivo delivery of bioactive recombinant proteins, antigenic determinants, among other things. This vector meets the requirements to construction of recombinant bacteria as live oral carriers. It has a strong constitutive promoter, high stability in E.

[Changes in the parameters of nonspecific protection of mice upon inoculation of double-stranded RNA from Saccharomyces cerevisiae yeasts].

The results of the study of the effect of double-stranded (ds) RNA from killer yeasts Sac. cerevisiae on the parameters of nonspecific protection are presented. Inoculation of dsRNA in a dose of 5 mg/kg intramuscularly was shown to induce interferon production, to increase body temperature, the activity of adrenal cortex, phagocytic activity of macrophages of the peritoneal exudate and blood neutrophils, the level of lysozyme in the blood, and the activity of macrophage acid phosphatase.

[Effect of exogenous RNA on the activity of poly(A).oligo(dT)-dependent DNA-polymerase in mouse tumors].

The effects of exogenous RNA on the poly(A).oligo(dT)-dependent DNA-polymerase activity of factor and factor-free carcinomas of the mammary gland of C3H mice and Ehrlich ascite carcinoma were studied. It was shown that after intraparenteral injection of the RNA the enzyme activity is increased in the oncornavirus-containing carcinomas and remains unchanged in the virus-free tumours.

[High-polymeric xenogenic RNA as an antitumor immunity stimulator].

To immunize CC57BR mice a suspension of live cells of Krebs-2 ascites tumour was administered intradermally into the tail partially amputated afterwards. The growth of the tumour transplanted intraperitoneally was inhibited by 23% only after twofold immunization. Single immunization with tumour cell incubated with the cattle liver RNA preparation in conjunction with intraperitoneal administration of RNA following tumour transplantation inhibited its growth by 43--53%, while twofold administration by 84--88%.