HsTX1

HsTX1 toxin, from the scorpion Heterometrus spinnifer, is a 34-residue, C-terminally amidated peptide cross-linked by four disulfide bridges. HsTX1 is an the inhibitor of potassium channel, with IC50 for Kv1.3 of 12 pM and inhibits TEM cell activation and attenuates inflammation in autoimmunity[1][2][3].

O=C([C@@H](N)C)N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N1[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N2[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H](C(NCC(N[C@H](C(N3[C@H](C(N[C@H](C(NCC(N[C@H]4CCCCN)=O)=O)CC5=CC=C(O)C=C5)=O)CCC3)=O)CSSC[C@H](NC6=O)C(N)=O)=O)=O)[C@@H](C)O)=O)CCC(O)=O)=O)CCCCN)=O)CCCNC(N)=N)=O)CSSC[C@H](NC7=O)C(N[C@H](C(N[C@H]6CCCNC(N)=N)=O)CC(N)=O)=O)=O)CCC2)=O)CC(O)=O)=O)C)=O)CSSC[C@H](NC8=O)C(N[C@H]7CCCCN)=O)=O)CC(O)=O)=O)CCCCN)=O)CCC1)=O)[C@@H](C)O)=O)CCCNC(N)=N)=O)CSSC[C@H](NC4=O)C(N[C@H](C(N[C@H](C(N[C@H](C(N[C@H]8CCCCN)=O)CCCNC(N)=N)=O)CC(N)=O)=O)CCSC)=O)=O)CO

[1]M Harunur Rashid, et al. A potent and Kv1.3-selective analogue of the scorpion toxin HsTX1 as a potential therapeutic for autoimmune diseases. Sci Rep. 2014 Mar 28:4:4509. doi: 10.1038/srep04509.|[2]Lebrun, Bruno, et al. A four-disulphide-bridged toxin, with high affinity towards voltage-gated K+ channels, isolated from Heterometrus spinnifer (Scorpionidae) venom. Biochemical Journal. 328 (Pt 1): 321–327.|[3]Mark R. Tanner, et al. Prolonged immunomodulation in inflammatory arthritis using the selective Kv1.3 channel blocker HsTX1[R14A] and its PEGylated analog. Immunol. 2017 Jul; 180: 45–57. Published online 2017 Apr 4.