Overview
Cat #:
STI-400
Alternative Name K+ channel toxin α-KTx 1.3, IbTx
Lyophilized Powder yes
Origin Synthetic peptide
MW: 4230.9 Da
Purity: >98% (HPLC)
Effective concentration 50-100 nM.
Sequence ZFTDVDCSVSKECWSVCKDLFGVDRGKCMGKKCRCYQ.
Modifications Disulfide bonds between: Cys7-Cys28, Cys13-Cys33, and Cys17-Cys35. Z = Pyrrolidone carboxylic acid.
Structure
Molecular formula C179H274N50O55S7
CAS No.: 129203-60-7
Activity Iberiotoxin is a potent selective blocker of the high conductance Ca2+-activated K+ channels (maxi-K).
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.
Our bioassay
Alomone Labs Iberiotoxin inhibits KCa1.1 channels (mSlo) heterologously expressed in Xenopus oocytes.A. Time course of KCa1.1 channel current amplitude before (black), during (green, marked by horizontal bar) application of 100 nM Iberiotoxin (#STI-400) for 200 sec and upon wash of the toxin. Currents were elicited every 10 sec by ramp stimulation to +100 mV from a holding of –100 mV for 100 msec. B. Superimposed example current responses before (black) and during (green) application of 100 nM Iberiotoxin (taken from the experiment in A).
Scientific background Iberiotoxin is a 37 amino acid peptidyl toxin isolated from the scorpion Mesobuthus tamulus and was shown to block large conductance Ca2+-activated K+ channels in smooth muscle cells1. Later it was shown to specifically block KCa1.1 (Slo) channels with Ki of about 1 nM2. In addition, experiments with cloned KCa1.1 channels demonstrate the strong effect of the sloβ subunits on the potency of block by Iberiotoxin3.
Target KCa1.1 K+ channels
Peptide Content: 100%
Lyophilized Powder
Image & Title 
Alomone Labs Iberiotoxin blocks BKCa channels in human chorionic plate arterial smooth muscle cells.Inhibition of BKCa channels with Iberiotoxin (#STI-400) which abolished outward currents at +80 mV by 61 ± 12%. Cells were voltage clamped at -60 mV and step depolarised from -70 mV to +80 mV for 500 ms in 10 mV increments and repolarised to -40 mV.Adapted from Brereton, M.F. et al. (2013) PLoS ONE 8, e57451. with permission of PLoS.
Alomone Labs Iberiotoxin blocks BKCa channels in human chorionic plate arterial smooth muscle cells.Inhibition of BKCa channels with Iberiotoxin (#STI-400) which abolished outward currents at +80 mV by 61 ± 12%. Cells were voltage clamped at -60 mV and step depolarised from -70 mV to +80 mV for 500 ms in 10 mV increments and repolarised to -40 mV.Adapted from Brereton, M.F. et al. (2013) PLoS ONE 8, e57451. with permission of PLoS.
For research purposes only, not for human use
Last Update: 31/01/2024
Specifications
Citations
Citations
