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Potassium channel toxin TsTXK-beta

Tityus serrulatus (Brazilian scorpion)
Reviewed-Annotation score: Annotation score: 3 out of 5-Experimental evidence at protein leveli


Specifically blocks voltage-gated potassium channels Kv4.2/KCND2. When measured at the peak current, the blocking effect of this toxin is about 65% and shows an IC50=652 nM (PubMed:27346450). However, when measured at a later moment of the depolarising test pulse (500 ms), a 100% block of the current is observed with an IC50=313 nM (PubMed:27346450). This may indicate a preference ot the toxin for binding the inactivated state of the channel. The inhibition is completely reversible (PubMed:27346450). Using intraplantar injections on rat, this toxin induces overt nociception (licking and lifting behaviors) and decreases the mechanical nociceptive threshold (hyperalgesia). Furthermore, the hyperalgesia is prolonged when intrathecal injections are performed (PubMed:27346450).2 Publications

Keywords - Molecular functioni

Ion channel impairing toxin, Neurotoxin, Potassium channel impairing toxin, Toxin, Voltage-gated potassium channel impairing toxin

Names & Taxonomyi

Protein namesi
Recommended name:
Potassium channel toxin TsTXK-beta
Alternative name(s):
Potassium channel toxin beta-KTx 1
Tityustoxin K-beta
Short name:
TsTX K beta
Short name:
TsTX-K beta
Short name:
Ts81 Publication
OrganismiTityus serrulatus (Brazilian scorpion)
Taxonomic identifieri6887 [NCBI]
Taxonomic lineageiEukaryotaMetazoaEcdysozoaArthropodaChelicerataArachnidaScorpionesButhidaButhoideaButhidaeTityus

Subcellular locationi

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti


PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 19Sequence analysisAdd BLAST19
PropeptideiPRO_000003534220 – 271 Publication8
ChainiPRO_000003534328 – 87Potassium channel toxin TsTXK-betaAdd BLAST60

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi56 ↔ 77By similarity
Disulfide bondi63 ↔ 82By similarity
Disulfide bondi67 ↔ 84By similarity

Keywords - PTMi

Disulfide bond


Tissue specificityi

Expressed by the venom gland.Curated

Family & Domainsi

Sequence similaritiesi

Keywords - Domaini


Family and domain databases

InterProiIPR029237. Long_scorpion_toxin.
[Graphical view]
PfamiPF14866. Toxin_38. 1 hit.
[Graphical view]


Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P69940-1 [UniParc]FASTAAdd to basket

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60 70 80
Mass (Da):9,729
Last modified:November 13, 2007 - v2

Mass spectrometryi

Molecular mass is 6716.15 Da from positions 26 - 85. Determined by ESI. 1 Publication


3D structure databases


Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Family and domain databases

InterProiIPR029237. Long_scorpion_toxin.
[Graphical view]
PfamiPF14866. Toxin_38. 1 hit.
[Graphical view]

Entry informationi

Entry nameiKBX1_TITSE
AccessioniPrimary (citable) accession number: P69940
Entry historyi
Integrated into UniProtKB/Swiss-Prot: January 4, 2005
Last sequence update: November 13, 2007
Last modified: November 30, 2016
This is version 38 of the entry and version 2 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program



It is not known if the sequenced fragment corresponding to the propeptide is the result of the post-translational maturation process, or if it has a biological activity of its own.1 Publication
Does not inhibit voltage-gated sodium channels tested (Nav1.2, Nav1.4, Nav1.6 and B.germanica BgNav) and most of the voltage-gated potassium channels tested (Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5, Kv1.6, Shaker, Kv2.1, Kv3.1, Kv7.1, Kv7.2, Kv7.4, Kv7.5, Kv10.1 and hERG). No hemolysis and no pore-forming activities are induced by this toxin.1 Publication

Keywords - Technical termi

Direct protein sequencing


  1. Scorpion potassium channel toxins
    Nomenclature of scorpion potassium channel toxins and list of entries
  2. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.