Overview

Cat #: STS-400-B

Alternative Name K⁺ channel toxin ShK, Toxin κ-stichotoxin-She3a, Kappa-stichotoxin-She3a, κ-SHTX-She3a

Lyophilized Powder yes

Origin Synthetic peptide

MW: 4563 Da

Purity: >98% (HPLC)

Form Lyophilized powder.

Effective concentration 1-100 nM.

Sequence RSCIDTIPKSRCTAFQCKHSMKYRLSFCRKTCGTC.

Modifications Disulfide bonds between Cys³-Cys³⁵, Cys¹²-Cys²⁸, and Cys¹⁷-Cys³².

Label LC-Biotin. The extent of labeling is 1 molecule of biotin per molecule of ShK.

Structure

Activity Stichodactyla Toxin blocks K_V1.3, K_V1.1, K_V1.4, and K_V1.6 at subnanomolar concentrations and K_V3.2 channels at 1000-fold higher concentration than that required to inhibit K_V1.3 channels^1-3.

References-Activity

Pennington, M.W. et al. (1995) Int. J. Pept. Protein Res. 46, 354.
Beeton, C. et al. (2003) J. Biol. Chem. 278, 9928.
Middleton, R.E. et al. (2003) Biochemistry 42, 13698.

Accession number P29187.

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 Stichodactyla Toxin-Biotin stains rat cerebellum.
Mildly fixed rat cerebellum sections were incubated with 25 nM Stichodactyla Toxin-Biotin (#STS-400-B) followed by streptavidin-Cy3 (red). Staining of Purkinje cells (vertical arrows) is seen acquired by A. 25x objective B. 40x objective. Using the 40x objective, grains scattered over the soma of purkinje cells can be seen (horizontal arrows). DAPI (blue) is used as the counterstain.
Direct flow cytometry of Stichodactyla toxin in live intact rat PC-12 cells.
^___ PC-12 cells.
^___ PC-12 cells + 100 nM ShK (Stichodactyla Toxin) (#STS-400) + 2 µg/ml Streptavidin, Alexa Fluor™ 647 conjugate.
^___ PC-12 cells + 2 µg/ml Streptavidin, Alexa Fluor™ 647 conjugate.
^___ PC-12 cells + 100 nM Stichodactyla Toxin-Biotin (#STS-400-B) + 2 µg/ml Streptavidin, Alexa Fluor™ 647 conjugate.
Alomone Labs Stichodactyla Toxin-Biotin blocks K_V1.3 channels expressed in Xenopus oocytes.
A. Representative time course of Stichodactyla Toxin-Biotin (#STS-400-B) inhibition of K_V1.3 current. Membrane potential was held at -100 mV, current was elicited by a 100 ms voltage ramp to +60 mV every 10 sec, and significantly inhibited by 1 nM Stichodactyla Toxin-Biotin (green). B. Superimposed traces of K_V1.3 current following application of control (black) and of 1 nM Stichodactyla Toxin-Biotin (green), taken from the recording in A.

Scientific background

ShK (Stichodactyla Toxin) is a peptidyl toxin originally isolated from the nematocyst of the sea anemone Stichodactyla helianthus.¹

ShK blocks K_V1.3, K_V1.1, K_V1.4, and K_V1.6 at subnanomolar concentrations and K_V3.2 channels at 1000-fold higher concentration than that required to inhibit K_V1.3 channels. It has been shown to block K_V current in DRG neurons, to displace radioactive Dendrotoxin from brain synaptosomes¹and inhibit I¹²⁵-Charybdotoxin binding to Jurkat T lymphocytes with an IC₅₀ of 32 pM.^2,4

Evidence also suggests that native K_V currents in the central nervous system, which are predominantly carried by K_V1.2 channels, are highly sensitive to this toxin.⁵

A fluorescently labeled synthetic ShK is used to recognize and to sort K_V1.3 containing lymphocytes.^4,6

Target K_V1.1, K_V1.3, K_V1.4, K_V1.6 channels

Peptide Content: 100%

Lyophilized Powder

For research purposes only, not for human use

Last Update: 04/07/2024

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Stichodactyla Toxin-Biotin

Overview

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Scientific Background

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