NMR and circular dichroism studies of synthetic peptides derived from the third intracellular loop of the β-adrenoceptor

AbstractThe C-terminal part of the third intracellular loop of the β-adrenoceptor is capable of stimulating adenylate cyclase in the presence of phospholipid vesicles via the stimulatory guanine nucleotide binding protein (Gs) [Palm et al. (1989) FEBS Lett. 254, 89–93]. We have investigated the structure of synthetic peptides corresponding to residues 284–295 of the turkey erythrocyte adrenoceptor in micelles, trifluoroethanol and aqueous solution, by using 2D 1H NMR and CD. In the presence of phospholipid micelles the peptides display a C-terminal α-helical region, whereas the N-terminal part was found to be highly flexible