title: Revisiting cangitoxin, a sea anemone peptide: purification and characterization of cangitoxins II and III from the venom of Bunodosoma cangicum.
abstract: Sodium channel toxins from sea anemones are employed as tools for dissecting the biophysical properties of inactivation in voltage-gated sodium channels. Cangitoxin (CGTX) is a peptide containing 48 amino acid residues and was formerly purified from Bunodosoma cangicum. Nevertheless, previous works reporting the isolation procedures for such peptide from B. cangicum secretions are controversial and may lead to incorrect information. In this paper, we report a simple and rapid procedure, consisting of two chromatographic steps, in order to obtain a CGTX analog directly from sea anemone venom. We also report a substitution of N16D in this peptide sample and the co-elution of an inseparable minor isoform presenting the R14H substitution. Peptides are named as CGTX-II and CGTX-III, and their effects over Nav1.1 channels in patch clamp experiments are demonstrated.
authors.affiliation: Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, travessa 14, n: 321, CEP 05508-900, São Paulo, SP, Brazil. zaharenko@usp.br
authors.forename: André Junqueira
authors.initials: AJ
authors.lastname: Zaharenko
authors.forename: Wilson Alves
authors.initials: WA
authors.lastname: Ferreira
authors.forename: Joacir Stolarz
authors.initials: JS
authors.lastname: de Oliveira
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Konno
authors.forename: Michael
authors.initials: M
authors.lastname: Richardson
authors.forename: Emanuele
authors.initials: E
authors.lastname: Schiavon
authors.forename: Enzo
authors.initials: E
authors.lastname: Wanke
authors.forename: José Carlos
authors.initials: JC
authors.lastname: de Freitas
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002478:Cells, Cultured; D005591:Chemical Fractionation; D003064:Cnidarian Venoms / Q000737:chemistry* / Q000633:toxicity; D005727:Ganglia, Spinal / Q000187:drug effects / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000737:chemistry* / Q000633:toxicity; D018408:Patch-Clamp Techniques; D010446:Peptide Fragments / Q000737:chemistry; D020033:Protein Isoforms; D051381:Rats; D017208:Rats, Wistar; D012615:Sea Anemones; D015222:Sodium Channels / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D003064:Cnidarian Venoms; D009498:Neurotoxins; D010446:Peptide Fragments; D020033:Protein Isoforms; D015222:Sodium Channels