<unk>  binds to the Shaker K+ channel in Drosophila as well as to its mammalian homologue. It blocks this channel by binding with high affinity (Kd 24, Lys 27, and Arg 31. The ability of the<unk>  to block the ‘Shaker K’ channel suggests a docking mechanism whereby the toxin sits on the channel and then prevents its opening through flexible movements of the side chains thereby allowing for various protein-protein complexes to be enacted. AgTx2 has been found to undergo conformational changes when bound to the ‘Shaker K’ channel which suggests the induced fit model may be present in toxin-channel interaction. This mode of interaction goes along with and explains the flexible side chains. The amino acid make up of the toxin determines the way each interacts with Shaker K channels. In<unk> , for example, the arginine interacts electrostatically with the aspartate of the ‘Shaker K’ channel. The final blocking of the pore in the Shaker K + channel occurs via the side chain of Lys 27. Lys 27 interacts with the Shaker K by plugging the selectivity filter and hydrogen bonding with carbonyls of Tyr 395 of each potassium channel subunit. Important stabilizing hydrogen bonding between various residues on the AgTx2 and the subunits of the channel hold the toxin-channel complex together. Mutations in Arg24Ala, Lys27Met, and Asn30Ala increased the dissociation, or break-down, of the complex, suggesting they all play important roles in holding the toxin on the channel.
Agitoxin
Neurotoxin
Kurtoxin
Dinotoxin
Chlorotoxin
Saxitoxin
Alpha-neurotoxin
Toxin