This new volume of _Methods in Enzymology_ continues the legacy of this premier serial with quality chapters authored by leaders in the field. This volume covers G protein coupled receptors, and includes chapters on such topics as GPCR modelling, interactions with other molecules, virtual screening and GPCR activation. * Continues the legacy of this premier serial with quality chapters authored by leaders in the field * Covers G protein coupled receptors * Contains chapters on such topics as GPCR modelling, interactions with other molecules, virtual screening and GPCR activation.