Taicatoxin (TCX) is a snake toxin that blocks voltage-dependent L-type calcium channels and small conductance Ca2+-activated K+ channels. The name taicatoxin (TAIpan + CAlcium + TOXIN) is derived from its natural source, the taipan snake, the site of its action, calcium channels, and from its function as a toxin. Taicatoxin was isolated from the venom of Australian taipan snake, Oxyuranus scutellatus scutellatus. TCX is a secreted protein, produced in the venom gland of the snake. It lowers the plateau of the action potential, decreasing the duration and the concentration parameters in the heart muscle cells. It has been seen that the 16-kDa subunit exhibits phospholipase activity, inducing a release of acyl CoA and acyl carnitine, fact which has a negative effect on cell’s integrity and function. TCX is involved in the outer hair cell motility too, by blocking the calcium traffic and preventing the cell shortening and elongation.
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