ProTx-I
Protoxin I (ProTx I; β-theraphotoxin-Tp1a) is a toxin that was originally isolated from the venom of Thrixopelma pruriens (Peruvian green velvet tarantula). This toxin reversibly inhibits the tetrodotoxin (TTX)-resistant channel Nav1.8 (IC50 = 27 nM) and TTX sensitive Nav channels such Nav1.2, Nav1.5 and Nav1.7 with IC50 values between 50 and 100 nM. Furthermore, ProTx-I shifts the voltage dependence activity of T-type Cav3.1 channels (IC50= 50 nM) without affecting the voltage dependence of inactivation.
Peptides & proteins
Protoxin I, ProTx 1
Middelton R.E, et al. (2002) Two tarantula peptides inhibit activation of multiple sodium channels. Biochemestry.; Priest B.T., et al. (2007) ProTx-I and ProTx-II: gating modifiers of voltage-gated sodium channels. Toxicon.
RT