to determine whether g proteins regulated these current components in the absence of ligand binding , recording pipettes contained 0.1 mm gtp , guanosine 5'-o- ( thiodiphosphate ) ( gdp-beta-s ) , or guanosine 5'-o- ( thiotriphosphate ) ( gtp-gamma-s ) .
C0018353
gtp
C0079469
gtp-gamma-s