[Obtaining and characteristics of domestic preparation interferon alpha-2b with prolonged effect].

Pegylated interferon alpha-2b (PEG-IFN alpha-2b) is a domestic preparation of a modified recombinant interferon alpha-2b with prolonged effect. The preparation was obtained by N-terminal pegylation of IFN alpha-2b with polyethylene glycol (PEG). This paper presents the method of PEG-IFN alpha-2b synthesis and characteristics of the obtained product. PAAG electrophoresis, Western blot analysis and MALDI-TOF mass-spectrometry confirm that the preparation is an N-terminal pegylated IFN alpha-2b that contains no more than 10% of dipegylated IFN alpha-2b. The comparison of PEG-IFN alpha-2b with its foreign analogue has revealed the similarity of their biological activity and pharmacokinetic parameters.

Use of phage lambda CI857AprTcrN derivative for isolation of prophage-free cells.

A method for obtaining nonlysogenic bacteria from wild-type phage lysogenized strains using phage lambda with AprTcr markers and double amber-mutation in N gene is proposed. When the lysogenic culture is infected with antibiotic-resistant phage, the nonlysogenic cells present in the population are lysogenized and isolated on selective medium with Ap and Tc. Subsequent culturing of lysogenized cells on media without antibiotics leads to phage elimination due to its instability.

[Characteristics of the expression of the Ap- and Tc-genes of plasmid origin in lambda vectors]. / Osobennosti ékspressii Ap- i Tc-genov plazmidnogo proiskhozhdeniia v liambdovykh vektorakh.

Expression of Ap and Tc genes of the plasmid origin in lambda vectors where the effect of lac promoter and PL phage promoter can be traced has been studied. The different orientation of Ap gene relative to strong promoters (lac and PL) permitted the beneficial arrangement of Ap gene for its optimum expression to be established. The interfering interaction of the two closely arranged strong promoters, Ap gene and lac promoter, has been detected. This repressed considerably the expression of Ap gene. The enhanced expression of this gene has been observed under the effect of the removed PL phage promoter. The active expression of Tc gene has been only observed in clones with the recombinant lambda-pcv-20 molecule (without lac promoter), irrespective of the plasmid pcv-20 orientation. This, presumably, can be accounted for by the favourable secondary structure of the m-RNA of Tc gene providing the efficient translation.

Isolation of nonlysogenic bacteria from lambda-lysogenized strains using antibiotic-resistant phage.

A simple and efficient method for obtaining nonlysogenic bacteria from lambda-lysogenized strains using phage with an inserted antibiotic-resistant plasmid is described. When the lysogenic culture is infected with antibiotic-resistant phage, single non-lysogenic cells are lysogenized, isolated on selective medium, and cured of phage during incubation at 37 degrees C.

[Isolation of nonlysogenic bacteria from lysogenic ones using a phage carrying resistance to antibiotics]. / Poluchenie nelizogennykh bakterii iz lizogennykh pri pomoshchi faga, nesushchego ustoichivost' k antibiotikam.

The method for obtaining nonlysogenic bacteria from lysogenic ones by means of a phage carrying resistance to antibiotics is proposed. Solitary nonlysogenic cells in a lysogenic culture are lysogenized after the infection of the culture with a labeled phage and then harvested on a selective medium: under special conditions the phage is eliminated from the cells.