[Synthesis and biological activity of new analogs of beta-casomorphine-5]. / Sintez i biologicheskaia aktivnost' novykh analogov beta-kazomorfina-5.

Four new analogues of beta-cazomorphine-5 modified at the C-end with ethylenediamine- and glycine-containing derivatives were synthesized by the standard method of peptide chemistry (mixed anhydrides, carbodiimide, activated esters): H-Tyr-Pro-Phe-Pro-Gly-EtDA-Gly-II (I) H-Tyr-Pro-Phe-Pro-Gly-EtDA-Gly-Gly-II (II) H-Tyr-Pro-Phe-Pro-Gly-EtDA-Gly-Gly-CO-CH3 (III) H-Tyr-Pro-Phe-Pro-Gly-EtDA-Gly-Gly-CO-CH2-CH2-COOH (IV) The level of affinity and the degree of selectivity of the peptides towards the mu- and delta-opioid receptors of the rat brain lyophilized membranes were studied by the radioreceptor method. All the new peptides displayed analgetic activity, largely depending upon their structure.

[Synthesis of new fragments of VP1 protein fragments from foot and mouth disease virus type A22. Synthesis of fragments 134-139, 134-145, 140-145, 150-155, and 150-159]. / Sintez novykh fragmentov belka VP1 virusa iashchura tipa A22. Sintez fragmentov 134-139, 134-145, 140-145, 150-155, and 150-159.

Fragments 134-145 and 150-159 of the antigenic-region of the VP1 protein of the A22 foot-and-mouth disease virus were synthesized by classic methods of peptide chemistry with isobutyl chloroformate as a coupling reagent. After purification by HPLG and amino acid analysis, the free peptides H-Gly-Lys-Tyr-Ser-Ala-Gly-Gly-Leu-Gly-Arg-Arg-Gly-OH and H-Leu-Ala-Ala-Arg-Val-Ala-Lys-Gln-Leu-Pro-OH were conjugated with BSA by means of N,N-dicyclohexylcarbodiimide. The conjugates were used, with complete Freund adjuvant, for immunization on guinea pigs. The antibodies formed had a virus neutralization activity.

[Synthesis of a 17-member peptide (143-159)--the VP(1) protein fragment of A(12) foot-and-mouth disease virus. II. Condensation of fragments]. / Sintez 17-chlennogo peptida (143-159)--fragmenta belka VP1(1) virusa iashchura A(12). II. Kondensatsiia framentov.

A 17-membered peptide corresponding to the amino acid sequence of (143-159) site of protein VP1 of A12 foot-and-mouth disease virus has been obtained by mixed anhydride method condensations of the earlier synthesized fragments. A norleucine residue has been attached, as a label, to the ends of peptides obtained. The complete deprotection was performed by hydrogenation peptides' hydrochlorides and the products were purified by HPLC. The antigenic properties of the synthesized peptides are discussed.

[Various approaches to designing the functionally active determinants as illustrated by the influenza virus A(H3N2) hemagglutinin]. / Nekotorye podkhody v konstruirovanii funktsional'no-aktivnykh determinant na primere gemaggliutinina virusa grippa A(H3N2).

Hexapeptide Lys-Gly-Pro-Asp-Ser-Gly analogous to the immunodominant fragment 141-146 of the epitope A of the influenza virus A(H3N2) hemagglutinin is synthesized. Conjugated with thyroglobulin and hemocyanine, the hexapeptide induced formation of highly specific antibodies with heterolytic properties in CBA mice. Antihexapeptide antibodies interact not only with the homologous antigen but also with hemagglutinin and influenza virus. Choice of the hexapeptide sequence is discussed.

[Synthesis of poly (Lys-Ser-Glu) and study of its antigenic and immunogenic properties]. / Sintez poly (Lys-Ser-Glu) i izuchenie ego antigennykh i immunogennykh svoistv.

We have synthesized oligo- and polypeptides containing lysin, serine and glutamic acid residues. Di- and tripeptides were prepared by the successive elongation of C-terminus by means of the N,N'-dicyclohexylcarbodiimide or mixed anhydride methods. The oligopeptides were obtained by block condensation of pentafluorophenyl esters of tripeptides, and polypeptides by polycondensation of dipeptide 2,4,5-trichlorophenyl esters. The three amino acids (Lys, Ser, Glu) were shown to take part in formation of antigenic determinants, serine being probably the immunodominant amino acid, and dipeptide Ser-Glu- the most important component of the epitope Lys-Ser-Glu. Polypeptides (Lys-Ser-Glu)n induced cross-reacting or heteroclitic antibodies. The expression of immune response depended on genotype of experimental animals.

[Synthesis and catalytic activity of polypeptides of regular structure containing polyfunctional amino acids]. / Sintez i kataliticheskaia aktivnost' polipeptidov reguliarnogo stroeniia, soderzhashchikh polifunktsional'nye aminokisloty.

Synthesis and study of catalytic properties of a series of regular polypeptide which contain residues of polyfunctional amino acids forming the active centre of esterases are described viz. (Ala-Tyr-Glu)n, (His-Ser-Glu)n, (Glu-His-Glu)n, (His-Glu)n, (Ser-His-Glu)n, His-(Tyr-Glu)n. Possibility of constructing catalytically active model polypeptides which can substitute some hydrolytic enzymes is assessed. Monomers for polycondensation were been synthesized by carbodiimide method in solution, and polypeptides were obtained via 2,4,5-trichlorphenylates. Gel-filtration was used for fractionation of and molecular mass-determination of polypeptides. Catalytic properties of the synthetic polypeptides were studied in hydrolysis of p-NFA, Z-L-Ala-ONp, and Z-D-Ala-ONp. It was revealed that polypeptides (Ala-Tyr-Glu)n and (His-Ser-Glu)n possess, in hydrolysis of Z-L-Ala-ONp- and Z-D-Ala-ONp some enantioselectivity with the value of KD/KL 1.3 and 1.17, resp. The upper and lower limits of enantioselectivity as dependent of the molecular mass of the corresponding polypeptides have been determined.