Reconstitution of the purified receptor for calcium channel blockers

The purified receptor for calcium channel blockers from rabbit skeletal muscle was reconstituted into phospholipid vesicles. The reconstitution did not alter the stoichiometry of the peptide chains. [3H]PN 200-110 bound to one site with apparent KD and Bmax values of 9.8 nM and 980 pmol/mg protein, respectively. The binding was stereospecific. D-cis-diltiazem and (-) desmethoxyverapamil affected allosterically the binding of dihydropyridines. This demonstrates the coinsertion of specific binding sites for the three calcium channel blocker into phospholipid vesicles.