{"id":320,"date":"2013-07-19T16:25:42","date_gmt":"2013-07-19T07:25:42","guid":{"rendered":"http:\/\/120.29.164.89\/?p=320"},"modified":"2023-08-29T10:32:14","modified_gmt":"2023-08-29T01:32:14","slug":"320","status":"publish","type":"post","link":"https:\/\/www.peptide.co.jp\/en\/new-product\/320.html","title":{"rendered":"Kurtoxin"},"content":{"rendered":"

The First Peptidic T-type Ca2+<\/sup>-Channel Blocker<\/b><\/p>\n

Voltage-dependent Ca2+<\/sup>-channels are classified according to the nature of their \u03b11<\/sub> subunits. High voltage-activated channels (HVA) are composed of \u03b11A<\/sub>-\u03b11F<\/sub>\/\u03b11S<\/sub>, leading to L-, N-, P\/Q- and R-type channels. Peptidic blockers specific for each channel are commercially available List of Ion Channel Blockers<\/a>. Low voltage-activated channels (LVA) are encoded by \u03b11G<\/sub>-\u03b11I<\/sub>, which correspond to T-type channels. Although these channels are known to be blocked by Ni2+<\/sup> ions, until recently there was no peptidic blocker for this particular channel.<\/p>\n

Kurtoxin:<\/b><\/p>\n

    Lys-Ile-Asp-Gly-Tyr-Pro-Val-Asp-Tyr-Trp-Asn-Cys-Lys-Arg-Ile-Cys-Trp-Tyr-Asn-Asn-\r\n    Lys-Tyr-Cys-Asn-Asp-Leu-Cys-Lys-Gly-Leu-Lys-Ala-Asp-Ser-Gly-Tyr-Cys-Trp-Gly-Trp-\r\n    Thr-Leu-Ser-Cys-Tyr-Cys-Gln-Gly-Leu-Pro-Asp-Asn-Ala-Arg-Ile-Lys-Arg-Ser-Gly-Arg-\r\n    Cys-Arg-Ala<\/pre>\n
However, in 1998, a new T-type channel blocker,  kurtoxin<\/a>, was isolated from the venom of the South African scorpion (Parabuthus transvaalicus<\/i>). This compound is a 63 amino acid residue peptide with 4 intramolecular disulfide linkages[Nat. Neurosci.,<\/i> 1<\/b>, 668 (1998) ]. Using the expressed \u03b11G<\/sub> channel, the binding of kurtoxin was found to involve 1:1 stoichiometry with a Kd<\/sub> value of 15 nM. Almost complete inhibition by kurtoxin was observed for the \u03b11G<\/sub> channel at 350 nM, whereas the \u03b11H<\/sub> channel was blocked approximately 85% at the same concentration. \u03b11A<\/sub>– \u03b11C<\/sub> and \u03b11E<\/sub> Channels were not affected at 350 nM, indicating the specific blocking activity of kurtoxin for the expressed T-type channels. Because of the sequence similarity with \u03b1-scorpion toxins, kurtoxin binds to voltage-gated Na+<\/sup> channels and slows their inactivation. Later, it was clarified that this peptide interacts with both HVA and LVA channels in rat central and peripheral neurons: i) N- and L-type channel currents were partially inhibited by 250-500 nM peptide (Kd<\/sub>=456 nM and 72 nM, respectively), ii) P-type Ba2+<\/sup> current in Purkinje neurons was facilitated by 500 nM peptide (Kd<\/sub>=14 nM), and iii) Kd<\/sub> for thalamic T-type channels was 49 nM[J. Neurosci.,<\/i> 22<\/b>, 2023 (2002) ]. The reason for this discrepancy between two reports remains to be clarified, however. T-type channel blocking activity of kurtoxin is attractive because this peptide does interact with both expressed and native T-type channels.<\/p>\n
 Kurtoxin<\/a> is a useful blocker for T-type channels, especially when used in combination with the various blockers for HVA channels for further research investigations.<\/p>\n\n\n\n\n
Code<\/td>\nCompound<\/td>\nPackage<\/td>\n<\/tr>\n
4375-s<\/a><\/td>\nKurtoxin<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
Related Products<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n
Code<\/td>\nCompound<\/td>\nSelectivity<\/td>\nPackage<\/td>\n<\/tr>\n
4255-s<\/a><\/td>\nCalciseptine<\/td>\nL-type Blocker<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n
4310-s<\/a><\/td>\nCalcicludine<\/td>\nL-type Blocker<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n
4161-v<\/a><\/td>\n\u03c9-Conotoxin GVIA<\/td>\nN-type Blocker<\/td>\n0.5 mg vial<\/td>\n<\/tr>\n
4289-v<\/a><\/td>\n\u03c9-Conotoxin MVIIA<\/td>\nN-type Blocker<\/td>\n0.5 mg vial<\/td>\n<\/tr>\n
4284-v<\/a><\/td>\n\u03c9-Conotoxin SVIB<\/td>\nN-type Blocker<\/td>\n0.5 mg vial<\/td>\n<\/tr>\n
4256-s<\/a><\/td>\n\u03c9-Agatoxin IVA<\/td>\nP-type Blocker<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n
4294-s<\/a><\/td>\n\u03c9-Agatoxin TK<\/td>\nP-type Blocker<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n
4283-s<\/a><\/td>\n\u03c9-Conotoxin MVIIC<\/td>\nP\/Q-type Blocker<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n
4363-s<\/a><\/td>\nSNX-482<\/td>\nR-type Blocker<\/td>\n0.1 mg vial<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"
The First Peptidic T-type Ca2+-Channel Blocker<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[],"acf":[],"_links":{"self":[{"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/posts\/320"}],"collection":[{"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/comments?post=320"}],"version-history":[{"count":2,"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/posts\/320\/revisions"}],"predecessor-version":[{"id":4948,"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/posts\/320\/revisions\/4948"}],"wp:attachment":[{"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/media?parent=320"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/categories?post=320"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.peptide.co.jp\/en\/wp-json\/wp\/v2\/tags?post=320"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}