title: Synthesis of disulfide-bridged fragments of omega-conotoxins GVIA and MVIIA. Use of Npys as a protecting/activating group for cysteine in Fmoc syntheses.
abstract: The 3-nitro-2-pyridinesulphenyl (Npys) moiety is finding increasing utility as a protecting-activating group for cysteine, particularly in the synthesis of cyclic and unsymmetrical disulfides using the Boc strategy. This chemistry has been extended to peptides assembled by the Fmoc strategy. N-Terminal Cys(Npys) is introduced via Boc-Cys(Npys)-OPfp. Non-N-terminal Cys(Npys) is incorporated by reacting a resin-bound, fully protected Cys(Acm) peptide with NpysCl. This approach has been applied to the synthesis of four disulfide-bridged fragments of omega-conotoxins GVIA and MVIIA.
authors.affiliation: Lilly Research Centre Ltd., Eli Lilly & Co., Windlesham, Surrey, UK.
authors.forename: R G
authors.initials: RG
authors.lastname: Simmonds
authors.forename: D E
authors.initials: DE
authors.lastname: Tupper
authors.forename: J R
authors.initials: JR
authors.lastname: Harris
mesh_terms: D000595:Amino Acid Sequence; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis*; D010455:Peptides / Q000737:chemistry*; D020866:omega-Conotoxin GVIA; D020960:omega-Conotoxins
chemical_list: D004220:Disulfides; D010446:Peptide Fragments; D010455:Peptides; D020960:omega-Conotoxins; C078452:ziconotide; D020866:omega-Conotoxin GVIA; D003545:Cysteine