Temperature Sensitivity of Fruit Fly Gustatory Receptors

Abstract

subjected to hyperpolarizing and depolarizing transmembrane potentials. The structure underwent only minor changes under hyperpolarizing potential. However, under a depolarizing potential, we observed a large conformational change of the protein through the outward movement of the S4 helix by approximately 8 Angstroms. This transition led to a rearrangement of the internal saltbridge network and allowed more waters into the pore as well as an increased stability in the hydrogen bond pathways, suggesting that it is an open state. We validated our atomistic hHv1 models with a variety of experimental data, including gating charge measurements and binding of the known inhibitor, 2-GBI, at the intracellular side of the selectivity filter. Additional simulations of selected mutants under a depolarizing potential constructed from the generated open state model suggest lower proton conductivity.