Synthesis and construction of a novel multiple peptide conjugate system: strategy for a subunit vaccine design

We describe the design and synthesis of a novel well characterized multi-pe ptide conjugate (MPC) system containing antigens from human malaria parasit e and the Tar protein of HIV type-1 (HIV-1-Tat). Construction of the MPC ut ilizes Fmoc solid-phase peptide synthesis coupled with solution chemistry. In the first phase, a core template that serves as primary anchor for the s ynthesis and attachment of multiple antigens is synthesized. Serine(trityl) and multiple lysine branches with epsilon groups blocked during chain asse mbly are incorporated forming a tetrameric core. Cysteine whose side chain thiol serves to couple haloacetyl or S-protected haloacetyl peptides is add ed to complete assembly of the cure template. Modification to the coupling solvent, addition of key amino acid derivatives (N-[1-hydroxy-4-methoxybenz yl]) in the peptide sequence allows the synthesis of base peptides on the c ore template with molecular mass greater than 7500 kDa. Base peptides are t hen reacted with high performance liquid chromatography purified haloacetyl peptides to generate multiple peptide conjugates with molecular masses of 10 to 13 kDa. MPC constructs thus formed are further characterized by matri x assisted laser desorption-time of Eight mass spectroscopy (MALDI-MS), ami no acid analysis, size exclusion chromatography, and SDS-polyacrylamide gel electrophoresis (PAGE). To our knowledge, this is the first report describ ing a chemically well defined multiple conjugate system with potential For development of synthetic subunit vaccines. (C) 2000 Elsevier Science Inc. A ll rights reserved.