title: Synthesis and characterization of a disulfide bond isomer of omega-conotoxin GVIA.
abstract: Solid phase peptide synthesis and air oxidation of omega-conotoxin GVIA yielded, in addition to the desired product, an isomeric peptide which could be completely separated from the native toxin by repeated HPLC. A chymotrypsin-trypsin digest of this peptide, when subjected to HPLC peptide mapping, provided peptides identical with synthetic disulfide containing peptides predicted for the omega-conotoxin isomer containing C1-C2, C3-C5, C4-C6 cystinyl pairings. The 'shaking' potency (ED50 = 1500 pmoles/kg, i.c.v.) of the isomeric peptide upon cannulated rats was 1.3% of the potency of native conotoxin (ED50 = 20 pmoles/kg). Considering that all three disulfide pairings in the isomer are different from the native toxin, its retention of biological activity is of interest.
authors.affiliation: Department of Peptide Chemistry, BACHEM Bioscience Inc., Philadelphia, PA 19104.
authors.forename: M W
authors.initials: MW
authors.lastname: Pennington
authors.forename: S M
authors.initials: SM
authors.lastname: Festin
authors.forename: M L
authors.initials: ML
authors.lastname: Maccecchini
authors.forename: W R
authors.initials: WR
authors.lastname: Kem
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D008297:Male; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship; D020866:omega-Conotoxin GVIA
chemical_list: D010456:Peptides, Cyclic; D020866:omega-Conotoxin GVIA