Overview
- Klint, J.K. et al. (2015) Br. J. Pharmacol. 172, 2445.
Alomone Labs Hd1a Toxin inhibits NaV1.7 currents heterologously expressed in Xenopus oocytes.A. Time course of Hd1a Toxin (#STH-200) inhibition of NaV1.7 channels current. Membrane potential was held at -90 mV and current was elicited by a 100 ms voltage step to -10 mV, delivered every 2 sec. 1 µM Hd1a Toxin applied for 9 min, as indicated by the bar (green), causes gradual and reversible inhibition of current. B. Superimposed traces of NaV1.7 channel currents upon application of control (black) and of 1 µM Hd1a Toxin (green), taken from the recording shown in A.
Hd1a Toxin, also called µ-TRTX-Hd1a, is a peptide toxin that acts as a selective and potent blocker of voltage-gated NaV1.7 channels.
The Hd1a peptide is a member of the NaSpTx family 1 of spider venoms, originating from the Haplopelma doriae spider. The toxin inhibits human NaV1.7 by interacting with the S3b-S4 paddle motif in channel domain II. Hd1a structure contains an inhibitor cystine knot motif that is likely to confer high levels of chemical, thermal and biological stability1.
Human NaV1.7 shows properties as an analgesic target. Loss-of-function mutations in the SNC9A gene that encodes human NaV1.7 result in congenital indifference to all forms of pain. Thus, inhibitors of hNaV1.7 including Hd1a Toxin are likely to be useful analgesics for treating a range of pain conditions1,2.
