ABSTRACT
The term "kinins" is generally made in reference to either the nonapeptide bradykinin. Nearly all cells express kinin receptors that mediate the activities of both bradykinin and kallidin. Alternatively, the receptor binding environment might also be hydrophobic and thereby lead to similar conformational biases in the ligand. More recently, bradykinin B2 receptors have been cloned from both rat and human sources. The bradykinin receptor is a member of a family of receptors for which an intracellular interaction with a G-protein is a critical part of the signal transduction pathway following agonist binding. A hydrophobicity calculation on the amino acid sequence of the rat bradykinin receptor yielded seven segments, each of which were 21 to 25 contiguous residues with predominantly hydrophobic side chains. G-Protein-coupled receptors do not lend themselves to analysis by either nuclear magnetic resonance or x-ray crystallography due to their structural dependence on an intact cell membrane.
