RGD Reference Report - An inhibitor of the Kv2.1 potassium channel isolated from the venom of a Chilean tarantula. - Rat Genome Database

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An inhibitor of the Kv2.1 potassium channel isolated from the venom of a Chilean tarantula.

Authors: Swartz, K J  MacKinnon, R 
Citation: Swartz KJ and MacKinnon R, Neuron. 1995 Oct;15(4):941-9. doi: 10.1016/0896-6273(95)90184-1.
RGD ID: 405650276
Pubmed: PMID:7576642   (View Abstract at PubMed)
DOI: DOI:10.1016/0896-6273(95)90184-1   (Journal Full-text)

The Kv2.1 voltage-activated K+ channel, a Shab-related K+ channel isolated from rat brain, is insensitive to previously identified peptide inhibitors. We have isolated two peptides from the venom of a Chilean tarantula, G. spatulata, that inhibit the Kv2.1 K+ channel. The two peptides, hanatoxin1 (HaTx1) and hanatoxin2 (HaTx2) are unrelated in primary sequence to other K+ channel inhibitors. The activity of HaTx was verified by synthesizing it in a bacterial expression system. The concentration dependence for both the degree of inhibition at equilibrium (Kd = 42 nM) and the kinetics of inhibition (kon = 3.7 x 10(4) M-1s-1; koff = 1.3 x 10(-3) s-1), are consistent with a bimolecular reaction between HaTx and the Kv2.1 K+ channel. Shaker-related, Shaw-related, and eag K+ channels were relatively insensitive to HaTx, whereas a Shal-related K+ channel was sensitive. Regions outside the scorpion toxin binding site (S5-S6 linker) determine sensitivity to HaTx. HaTx introduces a new class of K+ channel inhibitors that will be useful probes for studying K+ channel structure and function.



Gene Ontology Annotations    Click to see Annotation Detail View

Molecular Function

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
Kcnb1Ratdelayed rectifier potassium channel activity enablesIDA PMID:7576642UniProt 

Objects Annotated

Genes (Rattus norvegicus)
Kcnb1  (potassium voltage-gated channel subfamily B member 1)


Additional Information