Antibodies Using MAP Technology

Generating antibodies to linear peptide sequences is straight forward. The linear peptide sequence is made, purified, solubilized in phosphate buffered saline (PBS, pH7.2) and then conjugated to a carrier protein (KLH, BSA, OVA). The conjugated material is injected into an animal and bleeds taken after the animal has been immunized and boosted several times. If the peptide has been successfully conjugated to the carrier protein an antibody to the injected peptide will almost always be generated.

The most critical step in the generation of an antibody is the conjugation of the peptide to the carrier protein. However what if the peptide sequence contains hydrophobic, basic or internal cysteine residues. These amino acid residues may be problematic with respect to conjugation to a carrier protein in PBS at pH7.2.

Also what if the peptide sequence is very short, not very immunogenic or is flanked by sequence with high homology to other proteins leaving only 4 to 5 amino acids unique to the targeted protein. In this case conjugation to the carrier peptide may not be problematic but the ratio of peptide to carrier is very low resulting in less peptide delivered to the animal.

One method that has been proven to overcome the above difficulties is the Multiple Antigenic Peptide technology (MAP). Using this technology the peptide is synthesized onto an inert peptide core. The core matrix can be used to generate dual, tetrameric or octameric branches of the linear peptide. Since the peptide is synthesized onto this core the amino acid composition of the targeted peptide is not problematic and any sequence can be produced. MAP technology also allows for a higher ratio of peptide to core resulting in more peptide delivered to the animal. This is a distinct advantage over carrier proteins especially when the sequences are short or not very immunogenic. MAP technology also allows for the synthesis of B or T cell epitopes to either the C or N terminus of the peptide to enhance the immunogenicity of the peptide. Short sequences can also be repeated several times on dual or tetrameric branches to increase both the ratio of peptide to core and to enhance the immunogenicity of the sequence.

MAP technology also can be used to deliver two peptides to an animal using the same core. On a tetrameric branched core two branches can be synthesized with one protein and then the second protein can be added after the completion of the first protein.

MAP technology may not be needed to generate most antibodies. However if you have a problematic peptide, a peptide that has not generated an antibody due to low conjugation to carrier proteins or conventional antibody protocols have not been successful in producing an antibody, a customized MAP protocol may be the solution to generating that difficult antibody.

For additional information, please call our Sales and Technical Support Specialists at 1-800-435-2080 or e-mail peptide@qcb.com or antibody@qcb.com .