title: Synthesis and disulfide structure determination of agelenin: identification of the carboxy-terminus as an amide form.
abstract: Agelenin, a blocker of the presynaptic calcium channel, is a 35-amino acid peptide having six cysteinyl residues recently isolated from the venom of the spider Agelena opulenta. However, it has not been confirmed whether the carboxy-terminus of this peptide is a free acid or amide. To elucidate this, we synthesized both peptides by a solid phase procedure, and compared their elution profiles with that of the natural product on RP-HPLC. The retention time on HPLC as well as the biological activity of the synthetic peptide-amide was found to be identical with those of natural agelenin, confirming that the carboxy-terminus of agelenin is amidated. The disulfide structure of agelenin was also determined to be linked between 3-19, 10-24 and 18-34, by comparing the tryptic peptide linked by two disulfide bonds with those synthesized by the selective formation of disulfide bonds.
authors.affiliation: University of Tokyo.
authors.forename: T
authors.initials: T
authors.lastname: Inui
authors.forename: K
authors.initials: K
authors.lastname: Hagiwara
authors.forename: K
authors.initials: K
authors.lastname: Nakajima
authors.forename: T
authors.initials: T
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Nakajima
authors.forename: S
authors.initials: S
authors.lastname: Sakakibara
mesh_terms: D000577:Amides / Q000737:chemistry; D000595:Amino Acid Sequence; D002264:Carboxylic Acids / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis; D013111:Spider Venoms / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D000577:Amides; D002264:Carboxylic Acids; D004220:Disulfides; D009498:Neurotoxins; D010455:Peptides; D013111:Spider Venoms; C077703:agelenin