[28] Multiple antigen peptide system

This chapter describes various methods for the preparation of multiple antigen peptides (MAPs), containing one (homomeric) and two or more linear peptides (heteromeric MAPs) in various orientations along with those containing cyclic structure (McAP, multiple cyclic antigen peptide). The chapter presents two general approaches (direct versus modular) for preparing MAPs. Most syntheses are achieved by a direct approach using a stepwise method in which MAPs are prepared sequentially, which is similar in practice to the synthesis of a single-chain peptide on a solid support. As MAPs are macromolecules and because side products accumulated during the assemblage stage are amplified, thus leading to microheterogenicity, considerable effort is required for purification.. For clinical or other nonimmunological applications, chemically unambiguous MAPs are desirable. Thus, there is a development of an indirect approach for the modular methods of synthesis for MAPs by ligating purified unprotected peptide segments to a MAP core matrix.