{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T01:23:30Z","timestamp":1773624210383,"version":"3.50.1"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1996,5,1]]},"abstract":"<jats:p>A novel peptide was purified and characterized from the venom of the scorpion Pandinus imperator. Analysis of its primary structure reveals that it belongs to a new structural class of K+-channel blocking peptide, composed of only 35 amino acids, but cross-linked by four disulphide bridges. It is 40, 43 and 46% identical to noxiustoxin, margatoxin and toxin 1 of Centruroides limpidus respectively. However, it is less similar (26 to 37% identity) to toxins from scorpions of the geni Leiurus, Androctonus and Buthus. The disulphide pairing was determined by sequencing heterodimers produced by mild enzymic hydrolysis. They are formed between Cys-4\u2013Cys-25, Cys-10\u2013Cys-30, Cys-14\u2013Cys-32 and Cys-20\u2013Cys-35. Three-dimensional modelling, using the parameters determined for charybdotoxin, showed that is it possible to accommodate the four disulphide bridges in the same general structure of the other K+-channel blocking peptides. The new peptide (Pi1) blocks Shaker B K+ channels reversibly. It also displaces the binding of a known K+-channel blocker, [125I]noxiustoxin, from rat brain synaptosomal membranes with an IC50 of about 10 nM.<\/jats:p>","DOI":"10.1042\/bj3150977","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:48:38Z","timestamp":1439243318000},"page":"977-981","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":71,"title":["A novel structural class of K+-channel blocking toxin from the scorpion <i>Pandinus imperator<\/i>"],"prefix":"10.1042","volume":"315","author":[{"given":"Timoteo","family":"OLAMENDI-PORTUGAL","sequence":"first","affiliation":[{"name":"Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, Universidad Nacional Autonoma de Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62271, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Froylan","family":"G\u00d3MEZ-LAGUNAS","sequence":"additional","affiliation":[{"name":"Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, Universidad Nacional Autonoma de Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62271, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Georgina B.","family":"GURROLA","sequence":"additional","affiliation":[{"name":"Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, Universidad Nacional Autonoma de Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62271, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lourival D.","family":"POSSANI","sequence":"additional","affiliation":[{"name":"Department of Molecular Recognition and Structural Biology, Institute of Biotechnology, Universidad Nacional Autonoma de Mexico, Avenida Universidad, 2001, Apartado Postal 510-3, Cuernavaca 62271, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/315\/3\/977\/728921\/bj3150977.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/315\/3\/977\/728921\/bj3150977.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,24]],"date-time":"2021-11-24T00:11:51Z","timestamp":1637712711000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/315\/3\/977\/32786\/A-novel-structural-class-of-K-channel-blocking"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1996,5,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1996,5,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj3150977","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1996,5,1]]}}}