when reconstituted phospholipid vesicles that contain purified beta-adrenergic receptors and the gtp-binding regulatory protein gs were preincubated with agonist before the addition of guanosine 5'-o- ( 3-thiotriphosphate ) ( gtp gamma s ) , the typical receptor-stimulated gtp gamma s binding reaction was preceded by an even more rapid burst of gtp gamma s binding .
C0018353
gtp
C0079469
gtp gamma s