[Presentation of HIV epitopes by HBcAg].

The hepatitis B core antigen (HBcAg) was used to present the HIV epitopes and mimics selected by phage display. The HIV epitopes were inserted into the el loop of HBcAg. The influence of insertions on the ability of chimeric HBcAg to assemble itself was studied. Special soft was made use of to detect the regularities between certain physical-and-chemical properties of amine-acid residua (belonging to an inserted alien peptide) and the presence or loss of the ability of HBcAg to assemble itself. Recommendations are provided of how to overcome difficulties related with the presentation of alien epitopes.

[Application of peptide phage libraries for obtaining peptides specific to mouse lung adenocarcinoma]. / Ispol'zovanie peptidnykh fagovykh bibliotek dlia polucheniia peptidov, spetsifichnykh k adenokartsinome legkogo myshei.

Peptides binding, in vivo, with mouse lung adenocarcinoma, were selected from a peptide phage library containing above 100 million of different permutations. The selected phages carrying specific peptides accumulated in the tumor node, after intravenous injections made in A/Sn mice with induced adenocarcinoma, and persisted there even in 24 h after injections; whereas, they were detected in small quantities or not detected at all in other tissues (e.g. lungs and muscles). The selected bacteriophages were shown to accumulate not only in the primary tumor node but also in the lung with multiple metastases. Finally, amino acid sequences of exposed peptides were defined.

[Determination of glycyrrhizic acid binding sites by a phage display method]. / Opredelenie uchastkov sviazyvaniia glitsirrizinovoi kisloty metodom fagovogo displeia.

Phages that expose peptides specifically interacting with glycyrrhizic acid (GA) were selected from a phage peptide library by affinity selection and ELISA. Amino acid sequence analysis of the selected peptides and human proteins with the SIM program revealed homology to tyrosine protein kinases, serine/threonine protein kinases, tyrosine phosphatases, and some receptors. Analysis of the peptide and virus protein sequences with the BLAST program showed that GA has affinity for various surface proteins of several human viruses such as HIV-1, hepatitis C virus, and herpesviruses.

[Immunogenetic properties of peptides mimicking a human immunodeficiency virus gp41 (HIV-1) epitope recognized by virus-neutralizing antibody 2F5]. / Immunogennye svoistva peptidov-imitatorov épitopa belka gp41 virusa immunodefitsita cheloveka (VICh-1), uznavaemogo neitralizuiushchim antitelom 2F5.

Phage display was used to obtain peptides mimicking a HIV-1 gp41 conserved epitope recognized by virus-neutralizing monoclonal antibodies (MCA) 2F5. Rabbits and mice were immunized with the peptides exposed on the surface of filamentous bacteriophages. Antibodies to gp41 were detected in the sera of immunized animals. The virus-neutralizing activity of the sera was examined.

[Localization of the HIV-1 gp120 conformational epitope recognized by virus neutralizing monoclonal antibodies 2G12]. / Lokalizatsiia konformatsionnogo épitopa glikoproteina gp120 VICh-1, uznavaemogo virusneitralizuiushchimi monoklonal'nymi antitelami 2G12.

A phage peptide library was used to select peptides interacting with virus-neutralizing monoclonal antibodies (mAb) 2G12 which recognize a discontinuous surface epitope of HIV-1 gp120. With the published X-ray data, gp120 regions involved in the antigenic determinant were predicted. Binding with mAb 2G12 was ascribed to Trh-297, Phe-383, Tyr-384, Arg-419, Ile-420, Thr-415, Leu-416, Pro-417, Lys-421, and Trp-112. Though distant in the gp120 sequence, these residues are close in space and form the 2G12 epitope on the gp120 surface.

[Localization of tick-borne encephalitis virus protein E antigenic determinant recognized by antihemagglutinating monoclonal antibodies using a phage-display peptide library]. / Lokalizatsiia antigennoi determinanty belka E virusa kleshchevogo éntsefalita, uznavaemoi antigemaggliutiniruiushchimi monoklonal'nymi antitelami, s pomoshch'iu peptidnoi fagovoi biblioteki.

Bacteriophages bearing peptides reacting with antihemagglutinating monoclonal antibodies (MAb) 10H10 to tick-borne encephalitis (TBE) virus protein E were selected from a phage-display peptide library by affinity selection and enzyme immunoassay. The library contained randomized peptides that are 6 amino acids long, fused with protein pIII and exposed on the surface of the bacteriophage. No significant homology between the sequences of selected peptides and TBE virus protein E was detected. Computer software was created to locate the conformation epitopes on the surface of protein E. Amino acids R73, C74, T76, M77, N103, C105, L107, and S112 were found to form a discontinuous epitope recognized by MAb 10H10. These amino acids are remote in the protein sequence but close in the tertiary structure and form a whole epitope located in the structural domain II of protein E. Presumably the localized amino acids bind to the cellular receptor for TBE virus.

[Restriction endonuclease Sst 12I from a strain of Streptomyces sp. recognizing the nucleotide sequence 5'-CTGCAG-3']. / Endonukleasa restriktsii Sst12I iz shtamma Streptomyces sp., uznaiushchaia posledovatel'nost' nukleotidov 5'-CTGCAG-3'.

A new restriction endonuclease Sst12I belonging to the II type and recognizing the sequence 5'-CTGCAG-3' was isolated from the bacterial strain Streptomyces sp. St-12. The enzyme hydrolyzes DNA between adenine and guanine residues; thus, it is a true isoschizomer of restrictase PstI. In contrast to PstI, the restriction endonuclease Sst12I hydrolyses DNA both at 37 degrees and 55 degrees C and remains active after long-term storage.

[Construction of peptide mimetics of an epitope of the human immunodeficiency virus (HIV-1) gp41 protein, recognized by virus-neutralizing antibodies 2F5]. / Polucheni peptidov-imitatorov épitopa belka gp41 virusa immunodefitsita cheloveka (VICh-1) uznavaemogo virusneitralizuiushchimi antitelami 2F5.

A phase peptide library was screened with virus-neutralizing monoclonal antibodies (MCA) 2F5 which recognize a conserved epitope of HIV-1 gp41. Phages that expose peptides specifically binding with MCA 2F5 were selected by ELISA. Amino acid sequence analysis revealed a homology to region 662-671 of HIV-1 HB10 gp160 for most peptides. The major role in recognition was ascribed to Asp-664, Lys-665, and Trp-666. The epitope-mimicking peptides were tested for immunogenicity. Antibodies to gp41 were detected in serum of immunized rabbits.

[Use of a phage peptide library in mapping the group-specific hemagglutinating domain of alpha-virus glycoprotein E2]. / Ispol'zovanie fagovoi biblioteki peptidov v kartirovanii gruppospetsificheskogo gemaggliutiniruiushchego domena glikoproteina E2 al'fa-virusa.

Phage display peptide library f88-4/15 (G. P. Smith, USA) was used for mapping the hemagglutination activity domain of glycoprotein E2 of alphaviruses. Using affinity selection and ELISA, we selected the clones binding monoclonal antibody 4H5 to Venezuelan equine encephalomyelitis virus and inhibiting alphavirus hemagglutinating activity. Analysis of the similarity between the peptides amino acid sequences with the alphavirus glycoprotein E2 sequences revealed a structural motive of 4 amino acid residues (HTSR) which was identified in the 85-88 region. Bacteriophages F36 and F19 contained motives corresponding to 102-SXXM-105 and 109-AXXP-112 regions in alphavirus proteins E2. These data permit us to propose that the detected regions are fragments of a group-specific alphavirus hemagglutination domain.

[Ability of a recombinant protein containing fragment 114-122 of myelin basic protein, to cause allergic encephalomyelitis in guinea pigs]. / O sposobnosti rekombinantnogo belka, soderzhashchego fragment 114-122 osnovnogo belka mielina, vyzyvat' allergicheskii éntsefalomielit u morskikh svinok.

Four genetic constructions have been designed, capable of producing in E. coli the hybrid beta-galactosidases containing the encephalitogenic determinant 114-122 of myelin basic protein. The ability of chromatography-purified proteins to cause allergic encephalomyelitis in guinea pigs has been investigated. Only one out of four proteins carrying at least one complete replica of encephalitogenic determinant did induce allergic encephalomyelitis in animals. Effects of the structural context of the encephalitogenic determinant on its functional activity are discussed.