SYNTHESIS OF A DIEPITOPE MULTIPLE ANTIGEN PEPTIDE-CONTAINING SEQUENCES FROM 2 MALARIA ANTIGENS USING FMOC CHEMISTRY

Multiple antigen peptides (MAP) consist of lysine residue cores with b ranching peptide arms and have been demonstrated to be efficient immun ogens as well as useful antigens for ELISA. Synthesis of diepitope MAP s with two different branching peptides has previously been described using combined Boc and Fmoc chemistry. Here, the synthesis of a tetram eric diepitope MAP based on Fmoc chemistry is described. A lysine core was synthesized with N-alpha- and N-epsilon-amino groups orthogonally protected by Fmoc and a recently described protection group, Dde, res pectively. On the N-alpha-amino groups, a sequence from the Plasmodium falciparum antigen Pf332 was synthesized with a capped N-terminus. Af ter removal of Dde, a sequence from the P. falciparum circumsporozoite protein was synthesized on the core. Amino acid analysis of the MAP d isplayed equimolar amounts of the two peptide sequences, indicating th e reliability of the protection group Dde. In ELISA, antibodies specif ic for either of the two malarial sequences reacted with the MAP. The major advantages of this approach for synthesis of diepitope MAPs are that only a panel of Fmoc-amino acid derivatives is required and that the more complicated cleavage procedure for Boc chemistry can be avoid ed.