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A six-member HLDF6 peptide, fragment of HL-60 cell differentiation factor, exhibited antimetastatic and immunomodulating effects.

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A study of antitumor properties of HLDF-6 was carried out in DBA/2 mice with transplantable ascites lympholeukemia P-388 as well as in tumor cell culture. Immunomodulating characteristics were evaluated. Five-fold administration of HLDF-6 peptide to tumor-bearing mice inhibited tumor growth thus extending survival. As a result metabolic activity decreased which was followed by longer survival of lympholeukemia P-388 cells and enhanced cytological effect of peritoneal macrophages on tumor cells of the same strain.

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Salmon calcitonin (sCT) was prepared in good yield and high purity by the condensation of Nalpha-Boc-cyclic decapeptide, Boc-C1SNLSTC7VLG-OH (1,7-disulfide), with protected docosapeptide (Psc)LSQE(OPse)LHK(Psc)LQTYPRTNTGSGTP-NH2 x 3TFA, followed by deprotection of Boc with trifluoroacetic acid and Psc/Pse with piperidine. The 2-(phenylsulfonyl)ethoxycarbonyl (Psc) and 2-(phenylsulfonyl)ethyl (Pse) protecting groups were recently developed. The two peptides were built up by stepwise and fragment condensation using appropriate Nalpha-Boc-amino acids and subsequent deprotection in solution. The synthetic sCT exhibited hypocalcemic potency of more than 4000 IU/mg in rats.

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A rational attempt to prepare FmocHis(piTrt)OH regiospecifically gave in fact the well-known tau-trityl isomer, and experiments with model systems indicate that the prospects for access to pi-trityl histidine derivatives, which would be of great value for the racemization-free synthesis of histidine-containing peptides, are poor.

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The authors developed a method for obtaining highly specific polyclonal antibodies reacting with different sites of human chorionic gonadotropin (HCG) and an immunometrical method for measuring HCG in human biological fluids, based on the use of these antibodies. The sensitivity of the method is 10-15 IU/liter HCG, specificity 100%, no cross reactions with LH or FSH were observed. The method was tried in testing urine samples for HCG in women at 1-2 to 34 weeks of gestations and in one cancer patient with the diagnosis of vesical mole.

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Nine peptides were synthesized for detailed mapping of VEE virus E2-2 and E2-6 sites responsible for the formation of protective antibodies that neutralize the virus and block hemagglutination. The sequence of the peptides over-lapped the regions of amino acid residues 30-75 and 202-250 of VEE virus E2 protein in which antigenic mutations caused by monoclonal antibodies to E2-2 and E2-6 sites had been mapped. None of the synthesized peptides reacted in the enzyme immunoassay with a panel of 17 Mabs to VEE virus E2 protein. However, eight peptides reacted with polyclonal antiviral serum and two of them elicited antiviral antibody production. The E2-2 site might be associated with amino acid residues 30-45, and the region of E2 residues 57-62 in which antigenic mutations are observed is not a linear type antigenic determinant, but participates in the formation of antigenic determinants of the conformational type. The mapping of residues 202-250 demonstrated that all the peptides in this region were well recognized by polyclonal antiviral serum. The residues 235-240 were shown to form a linear epitope which provided a crossover between VEE and EEE viruses and was not recognized by 19 types of monoclonal antibodies cross-reacting with VEE and EEE viruses.

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White rats were immunized against fragment of diazepam-binding inhibitor octadecaneuropeptide (ODN) with conjugate ODN bovine serum albumin. This rats have reduced reactions of fear and anxiety in stress model of "open field" and in conflict Vogel test; their pain sensitivity ("tail flick" test) was lowered. The number and intensity of generalized seizure reactions after injection of pentylenetetrazole were decreased. The results show that active immunization to endogenous ODN has stress--protective and anti-seizure effects.

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The biological activity of six synthetic peptides of the 124-144 region of the human interferon alpha-2 (IFN alpha-2) molecule was studied. Peptides were examined for their ability to inhibit mitogen induced proliferation of human blood cells in vitro. Only the peptide corresponding to the amino acid sequence 124-138 (2438) possessed IFN-like antiproliferative activity. Other tested synthetic peptides did not affect cell proliferation in this experimental system. As with the native IFN alpha-2 molecule, the inhibitory effect of the peptide 2438 was dose-dependent. On simultaneous addition of peptide 2438, antiproliferative activity of IFN alpha-2 was enhanced. Direct cytotoxic effects of synthetic peptide 2438 were not revealed. These results suggest that a synthetic peptide corresponding to the 124-138-amino acid sequence of the human IFN alpha-2 molecule serves as a cytostatic agent.

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C-terminal peptide fragments of the heavy chain (HA1) of influenza virus, subtypes H1 and H3, hemagglutinins were synthesized. Rabbits and guinea pigs immunized with peptides H3 (314-328) and H1 (314-328) conjugates with BSA developed high immune response to conjugated peptides. Solid-phase RIA demonstrated interaction of antisera to peptide H3 (314-328) with A/Aichi/2/68 virus which was inhibited by peptides H3 (314-328) and H3 (317-328) but not by H3 (320-328), that is, antibodies interacted predominantly with amino acids 317-323 HA1. Anti-H3 (314-328)-BSA showed a marked activity in H1 and NT with a number of H3 subtype viruses. Antisera to peptide H1 (314-328) reacted with A/PR/8/34 virus insignificantly and were also inactive in H1 and NT with subtype H1 viruses.

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Three peptides corresponding to the sequences 124-144, 124-138, 129-144 of the human leukocyte interferon alpha 2 (IFN-alpha 2) were synthesized. The synthesis was performed by DCC-HOBT coupling of protected peptide segments in solution. The segments were obtained by the active ester coupling methodology using base-labile 2-[4-(phenylazobenzyl)sulfonyl]ethyl (Pse) group as carboxyterminal protection. After complete deprotection with 1 M methanesulphonic acid in trifluoroacetic acid--thioanisol--m-cresol mixture the peptides were purified by reversed-phase chromatography. The studies of interaction of the peptides with rabbit antiserum against IFN-alpha 2 revealed at least one minor antigenic determinant within the 124-144 region of IFN-alpha 2 amino acid sequence. Rabbit antisera developed against peptides 124-138 and 129-144 showed ability of binding recombinant IFN-alpha 2 and neutralizing its antiviral activity. Free peptides or their conjugates with bovine serum albumine did not display antiviral activity, neither could they inhibit the activity of IFN-alpha 2.

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Immunogenic properties of synthetic peptides corresponding to areas 122-133, 136-147, and 154-164 of the heavy chain of A/Aichi/2/68 virus HA were studied in two biological models: rabbits and guinea pigs. Peptides 122-123 and 136-147 together comprise the nearly compete antigenic determinant A, and peptide 154-164 is a part of determinant B. Both animal species immunized with peptide conjugates with bovine serum albumin produced a high immune response to all hapten-peptides. Comparative studies of rabbit and guinea pig sera by hemagglutination-inhibition tests revealed differences in antibody titres (1:10-1:40 for rabbits and 1:512-1:1024 for guinea pigs), the highest titres in both models being observed with peptide 136-147. Examinations of the virus-neutralizing capacity of the sera showed this property to be possessed by anti-(136-147) and anti-(154-164)E, the anti-(136-147) being slightly more active both for rabbits and for guinea pigs.

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The antigenic properties of the synthetic peptides corresponding to the regions 122-133, 136-147, 154-164 of the virus A/Aichi/2/68 hemagglutinin heavy chain have been studied. The 122-133 and 136-147 peptides comprise together almost whole antigenic determinant A, while the 154-164 peptide is a part of determinant B. Rabbits immunized by the peptides conjugated with carrier-protein BSA gave the high immune response to hapten-peptides. Each antiserum reacted only with homologous conjugate. All the antipeptide serums reacted with the virus A/Aichi/2/68 fixed on the base. Conjugate of the 136-147 peptide reacted with the rabbit antiserum against the virus A/Aichi/2/68 rendering the direct evidence to location of at least one hemagglutinin antigenic determinant in the region 136-147.

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Solution syntheses of [Leu]enkephalin and its [D-Ala2]analogue were accomplished using a new 2-(4-chlorophenyl)sulfonylethoxycarbonyl (Cps) base-labile group for amino protection and a chromogenic acid-labile 4-(4-phenylazo)benzyloxybenzyl (Abz) group for carboxyl protection. The syntheses were performed by stepwise attachment of Cps-amino acids, which were introduced as pentachlorophenyl esters or as dicyclohexylammonium salts in the presence of tris(dimethylamino)chlorophosphonium perchlorate. To remove Cps-group, Abz-esters of Cps-peptides were treated with two molar equivalents of 1,8-diazabicyclo[5.4.0]undec-7-ene in dimethylformamide followed by neutralization of the base with an excess of 1-hydroxybenzotriazole; the deblocked amino components were then used without isolation. Fully deblocked pentapeptides were purified and characterized by HPLC, FAB mass spectra and amino acid composition.

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Advanced approaches to the synthesis and reconstruction of genetic material developed in the Institutes of Molecular Biology and Genetics during the past years are summarized. The evolution of methods for oligonucleotide synthesis and scopes for their use in gene production are discussed. The principles of localised mutagenesis methods developed in the Institute are described, such as: a) mutagenesis directed to the regulatory gene regions; b) segment-localized mutagenesis; c) mutagenesis directed by phosphotriester analogues of oligonucleotides. Examples of employing these methods for induction of regulatory mutants of phage lambda, production of fused genes, mutant interferon genes, construction of new DNA vectors, construction of hybrid H1-H3 subtype haemagglutinine gene of influenza virus etc. are presented. The approach to in vivo site-directed mutagenesis is experimentally substantiated.

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Peptides corresponding to sequences 122-133, 136-147, and 154-164 of the heavy chain of hemagglutinin of the A/Aichi/2/68 (H3N2) influenza virus have been synthesized by stepwise elongation of the peptide chain with Boc-amino acid activated esters or by condensation of peptide blocks by DCC/HOBt-method. A coloured C-protecting group, 2-[4-(phenylazo)-benzylsulfonyl]ethyl (PSE), was used, which is convenient in purification of synthetic peptides. After removal of terminal N-and C-protecting groups the side-protecting residues were cleaved off with 1 M trifluoromethanesulfonic acid in trifluoroacetic acid containing 10% thioanisole. Crude products were purified by preparative reversed-phase liquid chromatography. Synthesized peptides were conjugated with BSA.

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