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Protein

Chlorotoxin

Gene
N/A
Organism
Leiurus quinquestriatus quinquestriatus (Egyptian scorpion) (Deathstalker scorpion)
Status
Reviewed-Annotation score: Annotation score: 3 out of 5-Experimental evidence at protein leveli

Functioni

This toxin binds to the surface of glioma cells, and inhibits their proliferation without having effects on normal brain cells. In this context, this toxin has been described as a chloride channel inhibitor (probably ClC-3/CLCN3) by causing its internalization via caveolae (PubMed:16520829). It has also been described to selectively interact with MMP2 (in complex with MT1-MMP (MMP14) and TIMP2), to inhibit its enzymatic activity and to decrease its presence at the cell surface (PubMed:12454020).3 Publications

GO - Molecular functioni

GO - Biological processi

Complete GO annotation...

Keywords - Molecular functioni

Chloride channel impairing toxin, Ion channel impairing toxin, Metalloenzyme inhibitor, Metalloprotease inhibitor, Neurotoxin, Protease inhibitor, Toxin, Voltage-gated chloride channel impairing toxin

Names & Taxonomyi

Protein namesi
Recommended name:
Chlorotoxin
Short name:
CTX
Short name:
ClTx
OrganismiLeiurus quinquestriatus quinquestriatus (Egyptian scorpion) (Deathstalker scorpion)
Taxonomic identifieri6885 [NCBI]
Taxonomic lineageiEukaryotaMetazoaEcdysozoaArthropodaChelicerataArachnidaScorpionesButhidaButhoideaButhidaeLeiurus

Subcellular locationi

GO - Cellular componenti

Complete GO annotation...

Keywords - Cellular componenti

Secreted

Pathology & Biotechi

Biotechnological usei

When bioconjugated with the fluorescent molecular beacon Cy5.5, might be used as an optical imaging contrast agent to enable surgeons to intraoperatively distinguish cancer foci from adjacent normal tissue.1 Publication

Pharmaceutical usei

Is under phase II clinical trial by Sinai Medical Center and TransMolecular under the name TM-601. It crosses blood-brain and tissue barriers and binds to malignant brain tumor cells without affecting healthy tissue. Radioiodinated TM-601 is used to treat malignant glioma.

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
PeptideiPRO_00000449411 – 36ChlorotoxinAdd BLAST36

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi2 ↔ 19PROSITE-ProRule annotation1 Publication
Disulfide bondi5 ↔ 28PROSITE-ProRule annotation1 Publication
Disulfide bondi16 ↔ 33PROSITE-ProRule annotation1 Publication
Disulfide bondi20 ↔ 35PROSITE-ProRule annotation1 Publication

Keywords - PTMi

Disulfide bond

Expressioni

Tissue specificityi

Expressed by the venom gland.

Structurei

Secondary structure

136
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi9 – 12Combined sources4
Helixi13 – 20Combined sources8
Beta strandi22 – 25Combined sources4
Beta strandi27 – 29Combined sources3
Beta strandi32 – 34Combined sources3

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1CHLNMR-A1-36[»]
ProteinModelPortaliP45639.
SMRiP45639.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiP45639.

Family & Domainsi

Domaini

The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin.

Sequence similaritiesi

Belongs to the short scorpion toxin superfamily. Chloride channel inhibitor family.PROSITE-ProRule annotation

Keywords - Domaini

Knottin

Family and domain databases

InterProiIPR003614. Scorpion_toxin-like.
IPR007958. Scorpion_toxinS_Cl_inh.
[Graphical view]
PfamiPF05294. Toxin_5. 1 hit.
[Graphical view]
SUPFAMiSSF57095. SSF57095. 1 hit.
PROSITEiPS51200. SHORT_SCORPION_CHLORIDE. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

P45639-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30 
MCMPCFTTDH QMARKCDDCC GGKGRGKCYG PQCLCR
Length:36
Mass (Da):4,005
Last modified:November 1, 1995 - v1
Checksum:i14A9F57559C6E92A
GO

Sequence databases

PIRiA48850.

Cross-referencesi

Web resourcesi

Wikipedia

Chlorotoxin entry

Sequence databases

PIRiA48850.

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1CHLNMR-A1-36[»]
ProteinModelPortaliP45639.
SMRiP45639.
ModBaseiSearch...
MobiDBiSearch...

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Miscellaneous databases

EvolutionaryTraceiP45639.

Family and domain databases

InterProiIPR003614. Scorpion_toxin-like.
IPR007958. Scorpion_toxinS_Cl_inh.
[Graphical view]
PfamiPF05294. Toxin_5. 1 hit.
[Graphical view]
SUPFAMiSSF57095. SSF57095. 1 hit.
PROSITEiPS51200. SHORT_SCORPION_CHLORIDE. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiCTXL_LEIQU
AccessioniPrimary (citable) accession number: P45639
Entry historyi
Integrated into UniProtKB/Swiss-Prot: November 1, 1995
Last sequence update: November 1, 1995
Last modified: November 2, 2016
This is version 80 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

Miscellaneousi

Miscellaneous

Does not interact with MMP-1, MMP-3 and MMP-9.1 Publication

Keywords - Technical termi

3D-structure, Direct protein sequencing, Pharmaceutical

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  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.