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Origin Synthetic peptide
MW: 3948.7 Da
Purity: >98% (HPLC)
Effective concentration 1-100 nM.
Sequence EGECGGFWWKCGSGKPACCPKYVCSPKWGLCNFPMP.
Modifications Presumed disulfide bonds between Cys4-Cys19, Cys11-Cys24 and Cys18-Cys31 (disulfide bonds undetermined).
Structure
Molecular formula C178H248N44O45S7.
Activity Guangxitoxin-1E is a gating modifier of KV2.1 (KCNB1, IC50 of 1 nM), KV2.2 (KCNB2, IC50 of 3 nM) and KV4.3 (KCND3, IC50 of 10-20 fold higher concentration) channels. In pancreatic β cells it enhances glucose-stimulated insulin secretion by broadening the cell action potential and enhancing calcium oscillations1,2. The physiological modulation of KV2.1 channels during glucose-induced insulin secretion is MgATP-mediated3.
Shipping and storage Shipped at room temperature. Product as supplied can be stored intact at room temperature for several weeks. For longer periods, it should be stored at -20°C.
Solubility Any aqueous buffer. Centrifuge all product preparations before use (10000 x g 5 min).
Storage of solutions Up to two weeks at 4°C or three months at -20°C.
Currents were elicited by application of voltage ramp from a holding potential of -80 mV to 60 mV in 100 msec, delivered every 10 seconds. A. Time course of channel activity (current amplitude at +40 mV), before (black) and during (green) application of 100 nM Guangxitoxin-1E (#STG-200). B. Top, illustration of the voltage ramp protocol. Bottom, example of superimposed current traces before (black) and during (green) application of 100 nM Guangxitoxin-1E, taken from the experiment in A.
Scientific background Guangxitoxin-1E is a 36 amino acid peptidyl toxin isolated from the Chilobrachys jingzhao (Chinese earth tiger) tarantula venom and belongs to the huwentoxin-1 family. Guangxitoxin-1E is a gating modifier of KV2.1 (KCNB1, IC50 of 1 nM), KV2.2 (KCNB2, IC50 of 3 nM) and KV4.3 (KCND3, IC50 of 50 nM) channels1. In pancreatic β cells, it enhances glucose-stimulated insulin secretion by broadening the cell action potential and enhancing calcium oscillations1,2. The physiological modulation of KV2.1 channels during glucose-induced insulin secretion is MgATP-mediated3,4. No significant effect was found 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) channels1,2.
Image & Title Alomone Labs Guangxitoxin-1E blocks KV2 channels in mouse acute cortical brain slices.KV2 mediated currents in mouse pyramidal cells are blocked by 100 nM application of Guangxitoxin-1E (#STG-200) (grey trace). Voltage protocol is shown below.Adapted from Bishop, H.I.et al. (2015) J. Neurosci.35, 14922. with permission of the Society for Neuroscience.
Last update: 11/04/2021
Guangxitoxin-1E (#STG-200) is a highly pure, synthetic, and biologically active peptide toxin.
Bioassay Tested
Alomone Labs Guangxitoxin-1E inhibits KV2.1 channel currents expressed in Xenopus oocytes.Currents were elicited by application of voltage ramp from a holding potential of -80 mV to 60 mV in 100 msec, delivered every 10 seconds. A. Time course of channel activity (current amplitude at +40 mV), before (black) and during (green) application of 100 nM Guangxitoxin-1E (#STG-200). B. Top, illustration of the voltage ramp protocol. Bottom, example of superimposed current traces before (black) and during (green) application of 100 nM Guangxitoxin-1E, taken from the experiment in A.
