a portion of high affinity ltb4-r on pmn leukocyte membranes were converted to the low affinity state by gtp ( mean +/- se = 28.6 +/- 14.0 % ) and nonhydrolyzable gtp analogues , such as 5'-guanylylimidodiphosphate ( gmp-pnp ) , in a concentration-dependent , nucleotide-specific , and reversible manner , without altering the intrinsic binding affinities of either class .
C0018353
gtp
C0018366
gmp-pnp