耦合受體的活化

This proposal considers the activation of N coupled receptors due to binding withspecific ligands. A receptor can either be in the free state or bind to a ligand, itsconformation can be in the inactive or active state. To perform biological function,a bound receptor is expected to be activated and a free receptor should beinactive. The binding/unbinding rates and activation/deactivation rates of areceptor is affected by the states of its nearby receptors through physical orchemical interactions. Two minimal theoretical models are described in thisproposal. In Model I the receptors live in an environment where only one type ofligand exist, while in Model II there are two types of competing ligands, withweak-binding ligands at high concentration and strong-binding ligands at very lowconcentration. For Model I the main interest is the general equilibrium and timedependent response of receptor activity to changes in ligand concentration. ForModel II the goal is to find out the parameter regime in which the receptors arenot activated by the weak but abundant ligands, but ready to be activated by onlya few strong but scarce ligands. Model I is important for establishing fundamentalstatistical mechanical understanding of general activation problem for coupledreceptors. Model II is closely related to the important immunological problem of Tcell receptor activation.