2K9O: Solution structure of Vm24 synthetic scorpion toxin

Animal venoms are rich sources of ligands for studying ion channels and other pharmacological targets. Proteomic analyses of the soluble venom from the Mexican scorpion Vaejovis mexicanus smithi showed that it contains more than 200 different components. Among them, a 36-residue peptide with a molecular mass of 3864 Da (named Vm24) was shown to be a potent blocker of Kv1.3 of human lymphocytes (K(d) approximately 3 pM). The three-dimensional solution structure of Vm24 was determined by nuclear magnetic resonance, showing the peptide folds into a distorted cystine-stabilized alpha/beta motif consisting of a single-turn alpha-helix and a three-stranded antiparallel beta-sheet, stabilized by four disulfide bridges. The disulfide pairs are formed between Cys6 and Cys26, Cys12 and Cys31, Cys16 and Cys33, and Cys21 and Cys36. Sequence analyses identified Vm24 as the first example of a new subfamily of alpha-type K(+) channel blockers (systematic number alpha-KTx 23.1). Comparison with other Kv1.3 blockers isolated from scorpions suggests a number of structural features that could explain the remarkable affinity and specificity of Vm24 toward Kv1.3 channels of lymphocytes.
PDB ID: 2K9ODownload
MMDB ID: 77740
PDB Deposition Date: 2008/10/20
Updated in MMDB: 2009/11
Experimental Method:
solution nmr
Similar Structures:
Biological Unit for 2K9O: monomeric; determined by author
Molecular Components in 2K9O
Label Count Molecule
Protein (1 molecule)
Vm24 Scorpion Toxin
Molecule annotation
* Click molecule labels to explore molecular sequence information.

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