{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,6]],"date-time":"2026-10-06T17:30:18Z","timestamp":1791307818776,"version":"4.3.1"},"reference-count":30,"publisher":"Portland Press Ltd.","issue":"1","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2007,5,15]]},"abstract":"<jats:p>In the present work, we purified and characterized a novel toxin named hemicalcin from the venom of the Iranian chactoid scorpion Hemiscorpius lepturus where it represents 0.6% of the total protein content. It is a 33-mer basic peptide reticulated by three disulfide bridges, and that shares between 85 and 91% sequence identity with four other toxins, all known or supposed to be active on ryanodine-sensitive calcium channels. Hemicalcin differs from these other toxins by seven amino acids at positions 9 (leucine\/arginine), 12 (alanine\/glutamic acid), 13 (aspartic acid\/asparagine), 14 (lysine\/asparagine), 18 (serine\/glycine), 26 (threonine\/alanine) and 28 (proline\/isoleucine\/alanine). In spite of these differences, hemicalcin remains active on ryanodine-sensitive Ca2+ channels, since it increases [3H]ryanodine binding on RyR1 (ryanodine receptor type\u00a01) and triggers Ca2+ release from sarcoplasmic vesicles. Bilayer lipid membrane experiments, in which the RyR1 channel is reconstituted and its gating properties are analysed, indicate that hemicalcin promotes an increase in the opening probability at intermediate concentration and induces a long-lasting subconductance level of 38% of the original amplitude at higher concentrations. Mice intracerebroventricular inoculation of 300\u00a0ng of hemicalcin induces neurotoxic symptoms in vivo, followed by death. Overall, these data identify a new biologically active toxin that belongs to a family of peptides active on the ryanodine-sensitive channel.<\/jats:p>","DOI":"10.1042\/bj20061404","type":"journal-article","created":{"date-parts":[[2007,4,27]],"date-time":"2007-04-27T08:02:48Z","timestamp":1177660968000},"page":"89-96","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":75,"title":["Hemicalcin, a new toxin from the Iranian scorpion <i>Hemiscorpius lepturus<\/i> which is active on ryanodine-sensitive Ca2+ channels"],"prefix":"10.1042","volume":"404","author":[{"given":"Delavar","family":"Shahbazzadeh","sequence":"first","affiliation":[{"name":"Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 place Pasteur, Tunis, BP-74, 1002 Tunisia"},{"name":"Biotechnology Department, Institute Pasteur of Iran, P.O. Box 13164, Tehran, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Najet","family":"Srairi-Abid","sequence":"additional","affiliation":[{"name":"Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 place Pasteur, Tunis, BP-74, 1002 Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wei","family":"Feng","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine-Molecular Biosciences and Center for Children's Environmental Health, University of California Davis, One Shields Avenue, Davis, CA 95616, U.S.A."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Narendra","family":"Ram","sequence":"additional","affiliation":[{"name":"INSERM U607, Canaux Calciques, Fonctions et Pathologies, D\u00e9partement R\u00e9ponse et Dynamique Cellulaire, Commissariat \u00e0 l'Energie Atomique, 17 rue des Martyrs, 38054 Grenoble Cedex 09, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lamia","family":"Borchani","sequence":"additional","affiliation":[{"name":"Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 place Pasteur, Tunis, BP-74, 1002 Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michel","family":"Ronjat","sequence":"additional","affiliation":[{"name":"INSERM U607, Canaux Calciques, Fonctions et Pathologies, D\u00e9partement R\u00e9ponse et Dynamique Cellulaire, Commissariat \u00e0 l'Energie Atomique, 17 rue des Martyrs, 38054 Grenoble Cedex 09, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abolfazl","family":"Akbari","sequence":"additional","affiliation":[{"name":"Razi Vaccine & Serum Research Institute, 31975\/148 Karaj, Iran"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isaac\u00a0N.","family":"Pessah","sequence":"additional","affiliation":[{"name":"Department of Veterinary Medicine-Molecular Biosciences and Center for Children's Environmental Health, University of California Davis, One Shields Avenue, Davis, CA 95616, U.S.A."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michel","family":"De\u00a0Waard","sequence":"additional","affiliation":[{"name":"INSERM U607, Canaux Calciques, Fonctions et Pathologies, D\u00e9partement R\u00e9ponse et Dynamique Cellulaire, Commissariat \u00e0 l'Energie Atomique, 17 rue des Martyrs, 38054 Grenoble Cedex 09, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohamed","family":"El\u00a0Ayeb","sequence":"additional","affiliation":[{"name":"Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 place Pasteur, Tunis, BP-74, 1002 Tunisia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"288","published-online":{"date-parts":[[2007,4,26]]},"reference":[{"key":"2021112213183376100_B1","first-page":"327","article-title":"Clinical study of Hemiscorpion lepturus in Iran","volume":"93","author":"Radmanesh","year":"1990","journal-title":"J. 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