[Synthetic proteins with antiviral properties of alpha-interferons]. / Iskusstvennye belki, vosproizvodiashchie protivovirusnye svoistva alpha-interferonov.

Consensus sequence 30-36 LKDRHDF of human alpha-interferons is inserted into the C- and N-terminal sequences of the artificial protein albeferon using genetic engineering methods in order to obtain artificial proteins with antiviral activity. Albeferon, obtained by Dolgikh et al. (Protein Eng., 1996, vol. 9, pp. 195-201), already contains the IFN-alpha 2 130-137 fragment and possesses antiproliferative activity comparable with that of IFN-alpha 2. According to CD spectroscopy, both proteins have regular secondary structures similar to that of the precursor protein. They exhibit antiviral activities, and the activity of one of them is comparable with that of IFN-alpha 2. At the same time, their cytotoxic properties are displayed only at relatively high concentrations, which substantially exceed the minimal antiviral concentrations.

[Introduction of biologically active fragments of interferon-alpha2 and insulin into the artificial protein albebetin affects immunogenicity of the final construct]. / Vvedenie biologicheski aktivnykh fragmentov interferona-al'fa2 i insulina v sostav iskusstvennogo belka al'bebetina vliiaet na immunogennost' itogovoi konstruktsii.

The immunogenicity of the artificial protein albebetin and its derivatives with active peptide fragments was investigated. We also studied the influence of the peptides on the immunogenicity of the whole construct and contribution of each component to the immunogenicity. Two of three studied proteins contained active peptides from human IFN-alpha and insulin. Three continuous antigenic sites with different immunogenic potential were recognized in the chimerical proteins. The interferon fragment was the immunodominant site in the albeferon and albeferon-insulin molecules, while the insulin fragment displayed low immunogenic activity. All continuous B-epitopes are located at the boundaries of the secondary structure elements and at the predicted surface-located sites of albebetin molecule. Thus, peptide fragments attached to the artificial protein carrier can influence immunogenicity of the resulting construct.

[Effect of a biologically active interferon fragment on the structure of the synthetic protein carrier]. / Issledovanie vliianiia biologicheski aktivnogo fragmenta interferona na strukturu iskusstvennogo belka-nositelia.

A biologically active de novo protein albeferon was studied by physical techniques including CD spectroscopy in far and near ultraviolet regions and microcalorimetry. Albeferon was obtained by grafting an active octapeptide interferon fragment into a de novo protein albebetin used as a carrier. It was shown that attachment of the octapeptide into its molecule did not weaken albebetin but even slightly improved its structure and stability. The obtained results can be used for de novo protein design and improvement.

[Expression of mutant horse cytochrome c genes in Escherichia coli]. / Ekspressiia mutantnykh genov tsitokhroma c loshadi v Escherichia coli.

Here we describe genetically engineered constructs for the expression in Escherichia coli of genes for horse cytochrome c mutants. These constructs allow the expression of the cytochrome c genes together with hemeligase, an enzyme which covalently links heme to cytochrome. Careful selection of producer strains and the adjustment of the conditions of expression provided for expression levels of 10-15 mg of protein per liter of culture. This is by an order of magnitude greater than the expression previously achieved in yeast. A series of horse cytochrome c mutants were obtained in this way.