guanine nucleotides reduced the binding of 125i-cck-octapeptide ( cck8 ) to acinar cell membranes , with the rank order of potency being guanyl-5'-yl imidodiphosphate ( gpp ( nh ) p ) greater than gtp greater than gdp greater than gmp .
C0018366
gpp ( nh ) p
C0018353
gtp