Abstract
AGA IVB is an important lead structure when considering the design of effectors of glutamate release inducting P/Q type calcium channels. The best route to achieve the analogues possessing the three-dimensional arrangement corresponding to the native binding loop was the introduction of constraint by ring formation via side chain to side chain lactamization for suitably protected Lys and Glu residues. Since tryptophane residue located at position 14 of this neuropeptide has been suggested as essential for binding, analogues in which this amino acid was replaced by aza-tryptophane and alanine were synthesized. The synthesis was carried out on various acid labile (BARLOS chlorotrityl, Rink amide, PEG based or Wang resins), by Fmoc strategy. In this paper, we describe optimization of the peptide cyclization with various protecting groups, and on resin or in solution cyclization experimental parameters. Copright 2007 European Peptide Society and John Wiley & Sons Ltd.