Guangxitoxin 1E

Guangxitoxin 1E: toxin properties

GxTx-1E was isolated from the venom of Chilobrachys jingzhao (Chinese earth tiger tarantula). It was shown to block Kv2.1/KCNB1, Kv2.2/KCNB2 and Kv4.3/KCND3 channels without significant effect on Kv1.2/KCNA2, Kv1.3/KCNA3, Kv1.5/KCNA5, Kv3.2/KCNC2, Cav1.2/CACNA1C, Cav2.2/CACNA1B, Nav1.5/SCN5A, Nav1.7/SCN9A or Nav1.8/SCN10A channels. GxTx-1E inhibits Kv2.1 with an IC₅₀ value of 1 nM and Kv2.2 with an IC₅₀ value of 3 nM. Block of Kv4.3 occurs at 10-20 fold higher concentrations. It acts as a gating modifier since it shifts the voltage-dependence of Kv2.1 K⁺ currents towards depolarized potentials. In pancreatic b cells, it enhances glucose-stimulated insulin secretion by broadening the cell action potential and enhancing calcium oscillations.

Therapeutic area

Diabetes type 2

Product Specifications

AA sequence: H-Glu-Gly-Glu-Cys⁴-Gly-Gly-Phe-Trp-Trp-Lys-Cys¹¹-Gly-Ser-Gly-Lys-Pro-Ala-Cys¹⁸-Cys¹⁹-Pro-Lys-Tyr-Val-Cys²⁴-Ser-Pro-Lys-Trp-Gly-Leu-Cys³¹-Asn-Phe-Pro-Met-Pro-OH
(Presumed disulfide bridge pattern - but unsolved Cys⁴-Cys¹⁹, Cys¹¹-Cys²⁴ and Cys¹⁸-Cys³¹)
Length (aa): 36
Formula: C₁₇₈H₂₄₈N₄₄O₄₅S₇
Molecular Weight: 3948.70 Da
Appearance: White lyophilized solid
Solubility: water and saline buffer
CAS number: not available
Source: Synthetic
Purity rate: > 95%

Prices & Quantities

• 50 µg: 100 €
• 5 x 50 µg: 400 €
• 100 µg: 170 €

Other quantities available upon request

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References

• Herrington J. (2009) Gating modifier peptides as probes of pancreatic beta-cell physiology. Toxicon 49(2):231-8.

• Zhuang GQ, Wu W, Liu F, Ma JL, Luo YX, Xiao ZX, Liu Y, Wang W, He Y. (2009) SNAP-25(1-180) enhances insulin secretion by blocking Kv2.1 channels in rat pancreatic islet beta-cells. Biochem Biophys Res Commun 20;379(4):812-6.

• Herrington J, Zhou YP, Bugianesi RM, Dulski PM, Feng Y, Warren VA, Smith MM, Kohler MG, Garsky VM, Sanchez M, Wagner M, Raphaelli K, Banerjee P, Ahaghotu C, Wunderler D, Priest BT, Mehl JT, Garcia ML, McManus OB, Kaczorowski GJ, Slaughter RS. (2006) Blockers of the delayed-rectifier potassium current in pancreatic beta-cells enhance glucose-dependent insulin secretion. Diabetes 55(4):1034-42.