title: Multiple bradykinin-related peptides from the capture web of the spider Nephila clavipes (Araneae, Tetragnatidae).
abstract: Three bradykinin-related peptides (nephilakinins-I to -III) and bradykinin itself were isolated from the aqueous washing extract of the capture web of the spider Nephila clavipes by gel permeation chromatography on a Sephacryl S-100 column, followed by chromatography in a Hi-Trap Sephadex-G25 Superfine column. The novel peptides occurred in low concentrations and were sequenced through ESI-MS/MS analysis: nephilakinin-I (G-P-N-P-G-F-S-P-F-R-NH2), nephilakinin-II (E-A-P-P-G-F-S-P-F-R-NH2) and nephilakinin-III (P-S-P-P-G-F-S-P-F-R-NH2). Synthetic peptides replicated the novel bradykinin-related peptides, which were submitted to biological characterizations. Nephilakinins were shown to cause constriction on isolated rat ileum preparations and relaxation on rat duodenum muscle preparations at amounts higher than bradykinin; apparently these peptides constitute B2-type agonists of ileal and duodenal smooth muscles. All peptides including the bradykinin were moderately lethal to honeybees. These bradykinin peptides may be related to the predation of insects by the webs of N. clavipes.
authors.affiliation: Institute of Immunological Investigations/MCT-CNPq, InCor-São Paulo University, São Paulo, SP, Brazil.
authors.forename: Evelyn C F R
authors.initials: EC
authors.lastname: Volsi
authors.forename: Maria Anita
authors.initials: MA
authors.lastname: Mendes
authors.forename: Maurício Ribeiro
authors.initials: MR
authors.lastname: Marques
authors.forename: Lucilene Delazari
authors.initials: LD
authors.lastname: dos Santos
authors.forename: Keity Souza
authors.initials: KS
authors.lastname: Santos
authors.forename: Bibiana Monson
authors.initials: BM
authors.lastname: de Souza
authors.forename: Eduardo Feltran
authors.initials: EF
authors.lastname: Babieri
authors.forename: Mario Sergio
authors.initials: MS
authors.lastname: Palma
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001920:Bradykinin / Q000032:analysis*; D017124:Conserved Sequence; D008969:Molecular Sequence Data; D011235:Predatory Behavior / Q000502:physiology*; D013112:Spiders / Q000737:chemistry* / Q000502:physiology*
chemical_list: D001920:Bradykinin