| Structural highlights
Function
[KA121_TITSE] Potently blocks Kv1.3/KCNA3, Kv1.2/KCNA2, and Shaker potassium channels (PubMed:24590385) and inhibits high conductance calcium-activated potassium channels (PubMed:10082164). The IC(50) of Kv1.3/KCNN3 and Kv1.2/KCNN2 are 0.55 nM and 6.19 nM respectively (PubMed:24590385). In addition, it stimulates the release of NO, IL-6 and TNF-alpha in J774.1 cells (PubMed:21549737) and presents a pro-inflammatory activity in mice (PubMed:23085190).[1] [2] [3] [4]
Publication Abstract from PubMed
The NMR structure of a new toxin, butantoxin (BuTX), which is present in the venoms of the three Brazilian scorpions Tityus serrulatus, Tityus bahiensis, and Tityus stigmurus, has been investigated. This toxin was shown to reversibly block the Shaker B potassium channels (K(d) approximately 660 nM) and inhibit the proliferation of T-cells and the interleukin-2 production of antigen-stimulated T-helper cells. BuTX is a 40 amino acid basic protein stabilized by the four disulfide bridges: Cys2-Cys5, Cys10-Cys31, Cys16-Cys36, and Cys20-Cys38. The latter three are conserved among all members of the short-chain scorpion toxin family, while the first is unique to BuTX. The three-dimensional structure of BuTX was determined using (1)H-NMR spectroscopy. NOESY, phase sensitive COSY (PH-COSY), and amide hydrogen exchange data were used to generate constraints for molecular modeling calculations. Distance geometry and simulated annealing calculations were performed to generate a family of 49 structures free of constraint violations. The secondary structure of BuTX consists of a short 2(1/2) turn alpha-helix (Glu15-Phe23) and a beta-sheet. The beta-sheet is composed of two well-defined antiparallel strands (Gly29-Met32 and Lys35-Cys38) connected by a type-I' beta-turn (Asn33-Asn34). Residues Cys5-Ala9 form a quasi-third strand of the beta-sheet. The N-terminal C2-C5 disulfide bridge unique to this toxin does not appear to confer stability to the protein.
NMR solution structure of butantoxin.,Holaday SK Jr, Martin BM, Fletcher PL Jr, Krishna NR Arch Biochem Biophys. 2000 Jul 1;379(1):18-27. PMID:10864437[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Novello JC, Arantes EC, Varanda WA, Oliveira B, Giglio JR, Marangoni S. TsTX-IV, a short chain four-disulfide-bridged neurotoxin from Tityus serrulatus venom which acts on Ca2+-activated K+ channels. Toxicon. 1999 Apr;37(4):651-60. PMID:10082164
- ↑ Zoccal KF, Bitencourt Cda S, Secatto A, Sorgi CA, Bordon Kde C, Sampaio SV, Arantes EC, Faccioli LH. Tityus serrulatus venom and toxins Ts1, Ts2 and Ts6 induce macrophage activation and production of immune mediators. Toxicon. 2011 Jun;57(7-8):1101-8. doi: 10.1016/j.toxicon.2011.04.017. Epub 2011, Apr 29. PMID:21549737 doi:http://dx.doi.org/10.1016/j.toxicon.2011.04.017
- ↑ Zoccal KF, Bitencourt Cda S, Sorgi CA, Bordon Kde C, Sampaio SV, Arantes EC, Faccioli LH. Ts6 and Ts2 from Tityus serrulatus venom induce inflammation by mechanisms dependent on lipid mediators and cytokine production. Toxicon. 2013 Jan;61:1-10. doi: 10.1016/j.toxicon.2012.10.002. Epub 2012 Oct 22. PMID:23085190 doi:http://dx.doi.org/10.1016/j.toxicon.2012.10.002
- ↑ Cerni FA, Pucca MB, Peigneur S, Cremonez CM, Bordon KC, Tytgat J, Arantes EC. Electrophysiological characterization of Ts6 and Ts7, K(+) channel toxins isolated through an improved Tityus serrulatus venom purification procedure. Toxins (Basel). 2014 Feb 28;6(3):892-913. doi: 10.3390/toxins6030892. PMID:24590385 doi:http://dx.doi.org/10.3390/toxins6030892
- ↑ Holaday SK Jr, Martin BM, Fletcher PL Jr, Krishna NR. NMR solution structure of butantoxin. Arch Biochem Biophys. 2000 Jul 1;379(1):18-27. PMID:10864437 doi:10.1006/abbi.2000.1858
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