Vanillotoxins (VaTxs, subtypes VaTx1, VaTx2, and VaTx3) are neurotoxins found in the venom of the tarantula Psalmopoeus cambridgei. They act as agonists for the transient receptor potential cation channel subfamily V member 1 (TRPV1), activating the pain sensory system. VaTx1 and 2 also act as antagonists for the Kv2-type voltage-gated potassium channel (Kv2), inducing paralytic behavior in small animals. All three subtypes of VaTxs act as agonists for TRPV1. EC50 of VaTx1, VaTx2, and VaTx3 for heterologously expressed TRPV1 channels is around 12, 2.5 and 0.3 μM, respectively.[1] VaTx1 and VaTx2 also bind to the Kv2 channel, although VaTx2 with a lower affinity than VaTx1. In humans, the effect of VaTxs has not been systematically studied. In general, the venom of P. cambridgei is known to produce pain, but the amount of toxin that is present in a bite is too low to cause serious health problems.
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