ω-Tbo-IT1

ω-Tbo-IT1 has been isolated from the venom of the Tibellus oblongus spider. ω-Tbo-IT1 is a selective blocker of insects calcium channels. It has been shown that ω-Tbo-IT1 has a potent insect toxicity with LD50 19 μg/g on house fly Musca domestica larvae and LD50 20 μg/g on juvenile Gromphadorhina portentosa cockroaches. Electrophysiological experiments revealed a reversible inhibition of evoked excitatory postsynaptic currents in blow fly Calliphora vicina neuromuscular junctions with an IC50 value 40 ± 10 nM.