[ 3h ] gtp [ guanosine triphosphate ] and [ 3h ] gmp-pnp [ guanosine 5'- ( beta , 8-imino ) triphosphate , a nonmetabolized analog of gtp ] have been utilized as ligands to characterize binding sites of guanine nucleotides to rat brain membranes .
C0018366
gmp-pnp
C0018353
gtp