Unique Mechanism of the Interaction between Honey Bee Toxin TPNQ and rKir1.1 Potassium Channel Explored by Computational Simulations: Insights into the Relative Insensitivity of Channel towards Animal Toxins
The 21-residue compact tertiapin-Q (TPNQ) toxin, a derivative of honey bee toxin tertiapin (TPN), is a potent blocker of inward-rectifier K+ channel subtype, rat Kir1.1 (rKir1.1) channel, and their interaction mechanism remains unclear. The interaction between honey bee toxin TPNQ and rKir1.1 channel was systematically investigated by the computational approaches. The diverse and ubiquitous potassium channels serve a variety of physiological and pharmacological functions [1]. These proteins are often targeted by numerous peptide toxins from the venomous animals, such as scorpions, spiders, sea anemones, honey bees, snakes and cone snails [2]. With more potassium channels as the therapeutic targets [8], the rational screening and design of peptide drugs, based on the structural information on the potassium channel-animal toxin interactions, exhibited an attractive prospect for disease diagnosis and treatment [9][12].