A novel Kv1.1 potassium channel blocking toxin from the venom of Palamneus gravimanus (Indian black scorpion)

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 fol...

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Bibliographic Details
Published in:Journal of Venomous Animals and Toxins including Tropical Diseases
Main Authors: S. S. More, K. K. Mirajkar, J. R. Gadag, K. S. Menon, M. K. Mathew
Format: Article in Journal/Newspaper
Language:English
Published: SciELO 2005
Subjects:
hKv1.1
K+ channel
PGT
TEVC
Palamneus gravimanus
Xenopus laevis oocytes
Indian black scorpion
Arctic medicine. Tropical medicine
RC955-962
Toxicology. Poisons
RA1190-1270
Zoology
QL1-991
Arctic
Indian
Online Access:https://doi.org/10.1590/S1678-91992005000300009
https://doaj.org/article/f4f89654b51f497bb61732e00ad4d508
Description
Summary: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.

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