RESUMO
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.
Assuntos
Epitopos/química , Hemaglutininas Virais/imunologia , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza A/imunologia , Sequência de Aminoácidos , Animais , Anticorpos Antivirais/imunologia , Ligação Competitiva , Ensaio de Imunoadsorção Enzimática , Hemaglutininas Virais/química , Camundongos , Camundongos Endogâmicos CBA , Dados de Sequência Molecular , Tireoglobulina/imunologiaRESUMO
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.
Assuntos
Epitopos/imunologia , Peptídeos/síntese química , Animais , Formação de Anticorpos , Reações Antígeno-Anticorpo , Imunização , Camundongos , Camundongos Endogâmicos CBA , Peso Molecular , Peptídeos/imunologia , Conformação Proteica , CoelhosRESUMO
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.