Characterization of a new leiurotoxin I-like scorpion toxin. PO5 from Androctonus mauretanicus mauretanicus.
Three novel peptide inhibitors of the SKCa channels were purified to homogeneity from the venom of the scorpion Androctonus mauretanicus mauretanicus using one step of RP-HPLC and competition assays with [125I]apamin to rat brain synaptosomes. PO1, PO2 and PO5 have K0.5 of 100, 100 and 0.02 nM, respectively, for the apamin binding site. The sequence of PO5 was established and compared to that of other scorpion toxins active on K+ channels: it contains 31 residues and has a free carboxyl end. it shares sequence similarity with apamin and leiurotoxin I.
Zerrouk
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H
Ingénierie des Protéines CNRS, URA 1455, Laboratoire de Biochimie, Faculté de Médecine Nord, Marseille, France.
Mansuelle
P
P
Benslimane
A
A
Rochat
H
H
Martin-Eauclaire
M F
MF
D000595:Amino Acid Sequence; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects*; D002851:Chromatography, High Pressure Liquid; D015640:Ion Channel Gating / Q000187:drug effects*; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000633:toxicity*; D012604:Scorpion Venoms / Q000737:chemistry* / Q000633:toxicity; D012605:Scorpions / Q000737:chemistry
D015220:Calcium Channels; D010455:Peptides; D012604:Scorpion Venoms; C080397:scorpion venom P05