释义 |
g protein noun Usage: usually capitalized G Etymology: guanosine triphosphate-binding protein : any of a class of cell membrane proteins that are coupled to cell surface receptors and upon stimulation of the receptor by an extracellular signalling molecule (as a hormone or neurotransmitter) bind to GTP to form an active complex which mediates an intracellular event (as activation of adenylate cyclase) |