• USA Home
  • I5904 - Iberiotoxin, recombinant from Mesobuthus tamulus

I5904 Sigma

Iberiotoxin, recombinant from Mesobuthus tamulus

≥98% (HPLC), recombinant, expressed in E. coli

Synonym: IbTX



Amino Acid Sequence

Glp-Phe-Thr-Asp-Val-Asp-Cys-Ser-Val-Ser-Lys-Glu-Cys-Trp-Ser-Val-Cys-Lys-Asp-Leu-Phe-Gly-Val-Asp-Arg-Gly-Lys-Cys-Met-Gly-Lys-Lys-Cys-Arg-Cys-Tyr-Gln [Disulfide Bridges: 7−28; 13−33; 17−35]

Biochem/physiol Actions

Exhibits the same activity as the natural form of the toxin

The single chain peptide iberiotoxin (IbTX) is a selective and reversible inhibitor of high-conductance calcium-activated potassium channels (PK,Ca). It occurs naturally in the venom of the scorpion Buthus tamulus. IbTX also modulates the binding of charybdotoxin (CbTX) to smooth muscle sarcolemmal membranes in a non-competitive manner. IbTX is similar in size to CbTX and shares considerable sequence homology with CbTX. However, IbTX differs in its overall charge in having one fewer basic and four more acidic residues than CbTX.


5, 10, 100 μg in glass bottle

Preparation Note

Soluble in aqueous buffers. Stock solutions of 1 μM can be aliquoted and stored at -20 °C for up to 3 months.

Features and Benefits

This compound is featured on the Potassium Channels page of the Handbook of Receptor Classification and Signal Transduction. To browse other handbook pages, click here.

Price and Availability

Safety & Documentation

Safety Information

GHS06  GHS06
Signal word 
Hazard statements 
Precautionary statements 
UN 3462 6.1 / PGII
WGK Germany 


Certificate of Analysis

Certificate of Origin

Protocols & Articles


Discover Bioactive Small Molecules for Ion Channels Research

Ion transport across the relatively impermeable lipid bilayer of the cell membrane is accomplished via membrane proteins known as ion channels, pumps and transporters. Ion channels are gated pores an...
Keywords: Biological processes, Cell signaling, Diseases, Hormones, Ligands, Neurotransmitters

Related Products

Technical Service:

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Bulk Ordering & Pricing:

Need larger quantities for your development, manufacturing or research applications?