{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,20]],"date-time":"2026-03-20T07:57:26Z","timestamp":1773993446344,"version":"3.50.1"},"reference-count":0,"publisher":"Rockefeller University Press","issue":"3","content-domain":{"domain":["rupress.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1996,3,1]]},"abstract":"<jats:p>We have studied potassium currents through a cloned Ca(2+)-dependent K+ channel (hslo) from human myometrium. Currents were recorded in inside-out macropatches from membranes of Xenopus laevis oocytes. In particular, the inactivation-like process that these channels show at high positive potentials was assessed in order to explore its molecular nature. This current inhibition conferred a bell shape to the current-voltage curves. The kinetic and voltage dependence of this process suggested the possibility of a Ba2+ block. There were the following similarities between the inactivation process observed at zero-added Ba2+ and the internal Ba2+ block of hslo channels: (a) in the steady state, the voltage dependence of the current inhibition observed at zero-added Ba2+ was the same as the voltage dependence of the Ba2+ block; (b) the time constant for recovery from current decay at zero-added Ba2+ was the same as the time constant for current recovery from Ba2+ blockade; and (c) current decay was largely suppressed in both cases by adding a Ba2+ chelator [(+)-18-crown-6-tetracarboxylic acid] to the internal solution. In our experimental conditions, we determined that the Kd for the complex chelator-Ba2+ is 1.6 x 10(-10) M. We conclude that the current decay observed at zero-added Ba2+ to the internal solution is due to contaminant Ba2+ present in our solutions (approximately 70 nM) and not to an intrinsic gating process. The Ba2+ blocking reaction in hslo channels is bimolecular. Ba2+ binds to a site (Kd = 0.36 +\/- 0.05 mM at zero applied voltage) that senses 92 +\/- 25% of the potential drop from the internal membrane surface.<\/jats:p>","DOI":"10.1085\/jgp.107.3.399","type":"journal-article","created":{"date-parts":[[2004,5,13]],"date-time":"2004-05-13T23:51:34Z","timestamp":1084492294000},"page":"399-407","update-policy":"https:\/\/doi.org\/10.1085\/jgp.crossmarkpolicy","source":"Crossref","is-referenced-by-count":41,"title":["Interaction of internal Ba2+ with a cloned Ca(2+)-dependent K+ (hslo) channel from smooth muscle."],"prefix":"10.1085","volume":"107","author":[{"given":"F","family":"Diaz","sequence":"first","affiliation":[{"name":"Centro de Estudios Cientificos de Santiago, Universidad de Chile."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Wallner","sequence":"additional","affiliation":[{"name":"Centro de Estudios Cientificos de Santiago, Universidad de Chile."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E","family":"Stefani","sequence":"additional","affiliation":[{"name":"Centro de Estudios Cientificos de Santiago, Universidad de Chile."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"L","family":"Toro","sequence":"additional","affiliation":[{"name":"Centro de Estudios Cientificos de Santiago, Universidad de Chile."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R","family":"Latorre","sequence":"additional","affiliation":[{"name":"Centro de Estudios Cientificos de Santiago, Universidad de Chile."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"291","published-online":{"date-parts":[[1996,3,1]]},"container-title":["The Journal of general physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/107\/3\/399\/1769311\/399.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/107\/3\/399\/1769311\/399.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,26]],"date-time":"2023-07-26T11:11:03Z","timestamp":1690369863000},"score":1,"resource":{"primary":{"URL":"https:\/\/rupress.org\/jgp\/article\/107\/3\/399\/26557\/Interaction-of-internal-Ba2-with-a-cloned-Ca-2"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1996,3,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1996,3,1]]}},"URL":"https:\/\/doi.org\/10.1085\/jgp.107.3.399","relation":{},"ISSN":["0022-1295","1540-7748"],"issn-type":[{"value":"0022-1295","type":"print"},{"value":"1540-7748","type":"electronic"}],"subject":[],"published":{"date-parts":[[1996,3,1]]}}}