Wasp toxin mastoparan-X

To elucidate the G-protein activation mechanism
Living things must react adequately to maintain its life and health. Most of the environmental information is transmitted to intracellular networks via receptor proteins in the cell membrane. Seven-tranmembrane receptor, one of the primary receptor, activates the G-proteins located intracellular side of the membrane, that cascade in turn the information to the downstream messengers.

Mastoparan-x is the amphiphilic peptide with 14 amino-acids, isolated from the wasp toxin. Mastoparan-x has many biological activities, e.g. histamine release from the abdominal mast cell of rat. One of the activity of mastoparan-x is the direct binding to the G-protein and its activation. Because G-protein activation mechanism by mastoparan-x is thought to be similar to that by transmembrane receptors, studying mastoparan-x is exciting. Also, owing to its relatively low molecular weight, it is much more accessible with solid-state NMR than actual receptors (publications: Harada et al. (2006), Todokoro et al. (2006), Fujiwara et al. (2004)). The insight into the activation pathways of GPCR possibly contributes to drug discovery.