Ligands play a pivotal role in the activation of GPCRs. When a ligand binds to a GPCR, it induces a conformational change in the receptor, which then interacts with a G protein. This interaction facilitates the exchange of GDP for GTP on the G protein, leading to its activation. The activated G protein can then go on to activate or inhibit other intracellular enzymes, propagating the signal and catalyzing various cellular processes.
