[125I]PIP HOE 140, a high affinity radioligand for bradykinin B2 receptors.
A high affinity radioligand for bradykinin B2 receptors was prepared by coupling an activated ester of [125I]4-iodobenzoic acid to the amino terminus nitrogen of the potent B2 antagonist HOE 140. The ligand, [125I]para-iodophenyl HOE 140 ([125I]PIP HOE 140), bound to a homogeneous set of sites in guinea pig ileal membranes with an equilibrium dissociation constant of 15 pM and a maximal binding density of 193 fmole/mg protein. Competition studies with a number of BK-related peptides indicated that the ligand specifically labeled B2 receptors in the preparation. The results suggest that [125I]PIP HOE 140 will be a useful tool for future studies of B2 receptors.
Brenner
N J
NJ
Merck Research Laboratories, Department of New Lead Pharmacology, West Point, PA 19486.
Stonesifer
G Y
GY
Schneck
K A
KA
Burns
H D
HD
Ransom
R W
RW
D000595:Amino Acid Sequence; D000818:Animals; D001667:Binding, Competitive; D001920:Bradykinin / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000138:chemical synthesis / Q000378:metabolism / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D006168:Guinea Pigs; D007082:Ileum / Q000378:metabolism*; D007457:Iodine Radioisotopes; D007700:Kinetics; D008297:Male; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism; D011869:Radioligand Assay; D018002:Receptors, Bradykinin / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*
D007457:Iodine Radioisotopes; D018002:Receptors, Bradykinin; C084732:para-iodophenyl HOE 140; C065679:icatibant; D001920:Bradykinin