Structure of angiotensin II-binding site probed with diaminoalkanes

The nature of the hormone-binding site of detergent-solubilized angiotensin II receptor from the bovine adrenal cortex has been characterized using diaminoalkanes. Their affinity for the hormone-binding site showed a dramatic alteration depending on their chain length; at the hexamethylene stage, a maximum and competitive inhibition was observed. These results indicate that the angiotensin II receptors have a definite hydrophobic binding groove limbed with diagonally located two negative charges, and those hydrophobic and electrostatic forces may play an important role in the proper register between the receptor and hormone.