Chemically unambiguous peptide immunogen: preparation, orientation and antigenicity of purified peptide conjugated to the multiple antigen peptide system
| Autor: | Mauro Galantino, Wen Liu, Yi-An Lu, Zhi-Yi Shen, P. Clavijo, James P. Tam |
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| Rok vydání: | 1991 |
| Předmět: |
Alanine
chemistry.chemical_classification Antigenicity Vaccines Synthetic Immunogen Immunology Molecular Sequence Data Peptide Enzyme-Linked Immunosorbent Assay Transforming Growth Factor alpha Epitope chemistry.chemical_compound Biochemistry Antigen chemistry Antibody Specificity Mutation Peptide synthesis Animals Amino Acid Sequence Rabbits Peptides Molecular Biology Peptide sequence |
| Zdroj: | Molecular immunology. 28(6) |
| ISSN: | 0161-5890 |
| Popis: | We described a novel and simple approach to prepare chemically unambiguous peptide immunogen using the multiple antigen peptide (MAP) approach. This approach requires the conjugation of two purified components: a chloroacetylated oligomeric lysine core matrix and a synthetic peptide containing cysteine at either the carboxyl or amino terminus. The resulting MAP is structurally unambiguous and contains a quantifiable amount of peptide antigens. Furthermore, this method also provides a flexible strategy to link a peptide antigen to the core matrix at the desirable orientation to mimic the native molecule. The carboxyl fragment 43-50 of human transforming growth factor alpha (TGF alpha) was used as a test model for this approach. Antipeptide antibodies did not recognize the "reverse immunogen" in which the peptide was attached to the MAP core matrix at a reverse orientation. To determine the specificity of the antibodies, we used two series of point-substituted TGF alpha analogs containing either alanine or the corresponding D-amino acid replacement to map the antigenic site. The alanine analogs were used to determine the contribution of the side chain while the D-amino acid analogs were used to determine the importance of backbone conformation. The antigen site was found to consist of four residues (Asp47-Leu48-Leu49-Ala50) at the distal end of the peptide-MAP conjugate. The results provide a clear explanation for the specificity of the antipeptide antibodies and their failure to recognize the "reverse immunogen" since the distal and the flexible end of the peptide-MAP construct constitutes the antigenic site. Furthermore, our results also suggests a strategy of placing the antigenic portion of a short-peptide at the distal end in the MAP approach to prepare immunogen. |
| Databáze: | OpenAIRE |
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