Patent ID: 6569993
Filing Date: 2003-05-27
Classification: C07K

Abstract:
A method for preparing a peptide having the formula: wherein J, L, and M are linear peptide fragments, and K2 is a cyclic peptide fragment; this method comprising the steps of:(1) preparing â€ƒby sequential attachment of suitably protected amino acid residues to a resin to provide: where â€ƒis a suitable peptide synthesis resin and M is a peptide fragment; (2) preparing separately by conventional peptide synthesis an N-terminally protected cyclic peptide of formula IV wherein P is a suitable amine protecting group, (3) coupling peptide III with peptide IV to provide a peptide of formula V (4) either (a) preparing peptide fragments J and L as a single peptide of formula VI â€ƒthen removing the protecting group from the N-terminus of peptide V and coupling peptide VI to the thus deprotected derivative of peptide V to provide a peptide of formula VII or (b) removing the protecting group from the N-terminus of peptide V and adding the protected individual amino acid elements of peptides J and L sequentially to the thus deprotected derivative of peptide V (using appropriate deprotection between individual additions), or (c) separately preparing either or both of peptides J and L as peptide fragments and coupling these peptide fragments to the growing peptide starting with the peptide of formula V; and (5) cleaving the resulting peptide from the resin, deprotecting said peptide and recovering it from the reaction medium.