A novel Kv1.1 potassium channel blocking toxin from the venom of Palamneus gravimanus (Indian black scorpion)
S. More, S.; K. Mirajkar, K.; R. Gadag, J.; S. Menon, K.; K. Mathew, M..
J. Venom. Anim. Toxins incl. Trop. Dis.;
11(3)2005.
Artigo
em Inglês
| VETINDEX
| ID: vti-443034
Resumo
A peptide toxin was isolated from the venom of Palamneus gravimanus, the Indian black scorpion, to block human Kv1.1 channels expressed in Xenopus laevis oocytes. A 4.5 kD peptide (toxin), as confirmed by SDS-PAGE, was purified to homogeneity by ion exchange chromatography using CM-Sephadex C-25 followed by Sephadex G-50 gel filtration. Palamneus gravimanus toxin (PGT) selectively blocks the human cloned voltage-gated potassium channel hKv1.1 in a two-electrode voltage-clamp (TEVC) technique. The results obtained indicate that the toxin blocks the hKv1.1 channel at a nanomolar concentration range (Ki value of 10 nM) of the peptide to the external side of the cell. The blockage seems to be voltage-dependent. Comparative structure of PGT (a 4.5 kD peptide) with BTK-2 suggests a close relationship; therefore this toxin can be employed to investigate the hKv1.1 channel structure.
Biblioteca responsável:
BR68.1
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