Chemical synthesis and characterization of maurocalcine, a scorpion toxin that activates Ca2+ release channel/ryanodine receptors

FEBS Letters

Rochat, H.²  Bichet, D.¹  Chen, L.³  Di Luccio, E.²  De Waard, M.¹  Kharrat, R.⁴  Allen, P.D.⁵  Pessah, I.N.³  El Ayeb, M.⁴  Fajloun, Z.²  Lecomte, C.²  Sabatier, J.M.² 

[1] Laboratoire de Neurobiologie des Canaux Ioniques, INSERM U464, IFR Jean Roche, Faculté de Médecine Nord, Bd Pierre Dramard, 13916 Marseille Cedex 20, France;Laboratoire de Biochimie, CNRS UMR 6560, IFR Jean Roche, Faculté de Médecine Nord, Bd Pierre Dramard, 13916 Marseille Cedex 20, France;Department of Molecular Biosciences, School of Veterinary Medicine and Graduate Program in Neurosciences, One Shields Avenue, University of California, Davis, CA 95616, USA;Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, P.O. Box 74, 1002 Belvédère, Tunis, Tunisia;Department of Anesthesia, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA

关键词: Maurocalcine;    Scorpion toxin;    Ca2+ release channel/ryanodine receptor;    Synthetic peptide;    Lipid bilayer;    HPLC;    high-pressure liquid chromatography;    LD50;    50% lethal dose;    MCa;    maurocalcine;    a scorpion toxin from the venom of Scorpio maurus palmatus;    IpTx A;    imperatoxin A;    a scorpion toxin from the venom of Pandinus imperator;    sMCa;    synthetic maurocalcine;    RyR1;    type 1 ryanodine receptor;    RyR2;    type 2 ryanodine receptors;    SR;    sarcoplasmic reticulum;    Tx2-9;    a P-type Ca2+ channel blocker from the spider P. nigriventer;   

DOI  :  10.1016/S0014-5793(00)01239-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Maurocalcine is a novel toxin isolated from the venom of the chactid scorpion Scorpio maurus palmatus. It is a 33-mer basic peptide cross-linked by three disulfide bridges, which shares 82% sequence identity with imperatoxin A, a scorpion toxin from the venom of Pandinus imperator. Maurocalcine is peculiar in terms of structural properties since it does not possess any consensus motif reported so far in other scorpion toxins. Due to its low concentration in venom (0.5% of the proteins), maurocalcine was chemically synthesized by means of an optimized solid-phase method, and purified after folding/oxidation by using both C18 reversed-phase and ion exchange high-pressure liquid chromatographies. The synthetic product (sMCa) was characterized. The half-cystine pairing pattern of sMCa was identified by enzyme-based cleavage and Edman sequencing. The pairings were Cys3-Cys17, Cys10-Cys21, and Cys16-Cys32. In vivo, the sMCa was lethal to mice following intracerebroventricular inoculation (LD₅₀, 20 μg/mouse). In vitro, electrophysiological experiments based on recordings of single channels incorporated into planar lipid bilayers showed that sMCa potently and reversibly modifies channel gating behavior of the type 1 ryanodine receptor by inducing prominent subconductance behavior.

【 授权许可】

Unknown