Molecular Basis for Ligand Modulation of a Mammalian Voltage-Gated Ca Channel.

TitleMolecular Basis for Ligand Modulation of a Mammalian Voltage-Gated Ca Channel.
Publication TypeJournal Article
Year of Publication2019
AuthorsZhao, Y, Huang, G, Wu, J, Wu, Q, Gao, S, Yan, Z, Lei, J, Yan, N
Date Published2019 05 30
Keywords3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester, Amino Acid Sequence, Animals, Binding Sites, Calcium Channel Blockers, Calcium Channels, Calcium Channels, L-Type, Cryoelectron Microscopy, Diltiazem, Ligands, Male, Models, Molecular, Nifedipine, Rabbits, Verapamil

<p>The L-type voltage-gated Ca (Ca) channels are modulated by various compounds exemplified by 1,4-dihydropyridines (DHP), benzothiazepines (BTZ), and phenylalkylamines (PAA), many of which have been used for characterizing channel properties and for treatment of hypertension and other disorders. Here, we report the cryoelectron microscopy (cryo-EM) structures of Ca1.1 in complex with archetypal antagonistic drugs, nifedipine, diltiazem, and verapamil, at resolutions of 2.9 Å, 3.0 Å, and 2.7 Å, respectively, and with a DHP agonist Bay K 8644 at 2.8 Å. Diltiazem and verapamil traverse the central cavity of the pore domain, directly blocking ion permeation. Although nifedipine and Bay K 8644 occupy the same fenestration site at the interface of repeats III and IV, the coordination details support previous functional observations that Bay K 8644 is less favored in the inactivated state. These structures elucidate the modes of action of different Ca ligands and establish a framework for structure-guided drug discovery.</p>

Alternate JournalCell
PubMed ID31150622