[Immunochemical and biological properties of synthetic peptide fragments from the 124-144 sequence of human leukocyte interferon alpha2].

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.