[Antitumor properties of a liposomal form of a differentiation factor HLDF fragment in cultured cells].

Cytotoxic properties of a liposomal form of the HLDF6 hexapeptide, representing an HL-60 cell differentiation factor fragment, have been studied on a murine primary lymphosarcoma cell culture. It is established that the liposomal HLDF6 peptide is capable of inhibiting proliferation and enhancing death of the cells of both LS and RLS lymphosarcoma strains distinguished by their sensitivity to cytostatic agents. The effect of the preparation is determined by its antiproliferative and apoptogenic actions on the cells. Free HLDF6 peptide showed a lower cytotoxic activity with respect to the tumor cells as compared to the liposomal preparation.

[An intensification of antiviral and interferon effects of ridostin (an interferon inducer) by cationic liposomes in vitro and in intranasal administration]. / Usilenie kationnymi liposomami protivovirusnogo i interferonogennogo deistviia induktora interferona ridostina in vitro i pri intranazal'nom primenenii.

Combined application of ridostine with catonic liposomes was shown to essentially enhance the interferon-inducing and antiviral activity of the former in experiments with cell cultures L-929, which is apparently related with an improved efficiency of intracellular delivery of dsRNA. A comparative study demonstrated that ridostine, when combined with liposomes, is needed by 10(3)-10(4) times less as when it is used alone. A pretreatment of the cellular monolayer by cationic liposomes contributes also to enhancing the activity of ridostine, which can be explained by an enhanced permeability of cells for dsRNA holding on-for as long as 30 minutes after the removal of liposomes from the liquid culture. A separate successive administration of, first, liposomes and, then, of ridostine in BALB/c mice (20 mg/kg) leads to a more intensified induction of interferon in the upper respiratory tract tissues as compared with the administration of ridostine alone.

[Introduction of aminoalkyl groups into prepared synthetic oligodeoxyribonucleotides by transamination of cytosine residues]. / Vvedenie aminoalkil'nykh grupp v gotovye sinteticheskie oligodezoksiribonukleotidy putem pereaminirovaniia ostatkov tsitozina.

The bisulphite-catalysed transamination of cytosine residues by means of ethylenediamine generally used for the natural nucleic acids modification has been extended on relatively short synthetic oligonucleotides. One of the aminoalkyloligonucleotides thus obtained has been used for preparing a biotinylated hybridisation probe.

[Evaluation of the relative effectiveness of hybridization probes prepared by action of hydrazides of biotin derivatives on DNA]. / Otsenka otnositel'noi éffektivnosti gibridizatsionnykh zondov, poluchennykh deistviem gidrazidov proizvodnykh biotina na DNK.

Efficiencies of biotinylated DNAs as hybridisation probes in a model system of non-radioactive detection were compared. Probes were obtained by interaction of single-stranded DNA and each of four different hydrazides of biotin derivatives. The most sensitivity in detection of complementary target was obtained using (biocytin hydrazide)-treated DNA. Relations between hydrazide structures and sensitivity of biotinylated probes are discussed.

[Primary structure of the gene for protein VP1 from foot-and-mouth disease virus serotype O1 isolated in the USSR]. / Pervichnaia struktura gena belka VP1 virusov iashchura serotipa O1, izolirovannykh v SSSR.

The nucleotides sequence has been determined for the viral RNA and some of its cDNAs coding for the major antigenic protein of the epidemic stomatitis O1-194 and O1-1618 VP1 viruses. The expressed microheterogeneity has been registered for the population of the strain O1-194.

[The use of filamentous phage M13 in protein engineering]. / Ispol'zovanie nitchatogo faga M13 dlia belkovoi inzhenerii.

M13B1 vector based on the filamentous phage M13 has been constructed. M13B1 phage carries the gene of resistance to ampicillin and contains the unique site of recognition for BamHI restriction endonuclease in gene VIII coding for the major coat protein. BamHI restriction site has been inserted into the gene of the major coat protein by means of oligonucleotide directed mutagenesis. The synthetic DNA fragment coding for the model peptides has been inserted through BamHI site into the M13B1 DNA. The possibility of inserting foreign peptides into the N-terminus at maintaining the viability of hybrid phages has been shown. The differences in specificity of the recombinant phage maturation have been determined by analysing the amino acid sequence of B-protein.