Structural Basis of the Modulation of the Voltage‐Gated Calcium Ion Channel Cav1.1 by Dihydropyridine Compounds. (10th December 2020)

• Record Type: Journal Article
• Authors: Gao, Shuai; Yan, Nieng
• Is Part Of: Angewandte Chemie. Volume 133:Number 6(2021)
• Page Start: 3168
• Page End: 3174
• Publication Date: 2020-12-10
• Subjects: cryo-electron microscopy -- inhibitors -- nanodiscs -- structural biology -- voltage-gated calcium ion channels; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.202011793
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: 1, 4‐Dihydropyridines (DHP), the most commonly used antihypertensives, function by inhibiting the L‐type voltage‐gated Ca 2+ (Cav ) channels. DHP compounds exhibit chirality‐specific antagonistic or agonistic effects. The structure of rabbit Cav 1.1 bound to an achiral drug nifedipine reveals the general binding mode for DHP drugs, but the molecular basis for chiral specificity remained elusive. Herein, we report five cryo‐EM structures of nanodisc‐embedded Cav 1.1 in the presence of the bestselling drug amlodipine, a DHP antagonist ( R )‐(+)‐Bay K8644, and a titration of its agonistic enantiomer ( S )‐(−)‐Bay K8644 at resolutions of 2.9–3.4 Å. The amlodipine‐bound structure reveals the molecular basis for the high efficacy of the drug. All structures with the addition of the Bay K8644 enantiomers exhibit similar inactivated conformations, suggesting that ( S )‐(−)‐Bay K8644, when acting as an agonist, is insufficient to lock the activated state of the channel for a prolonged duration. Abstract : High‐resolution cryo‐EM structures of nanodisc‐embedded Cav 1.1 in complex with antagonists Levamlodipine, ( R )‐(+)‐Bay K8644, and dual agonist/antagonist ( S )‐(−)‐Bay K8644 reveal the molecular basis of the allosteric modulation of the voltage‐gated Ca 2+ channel Cav 1.1 by dihydropyridine (DHP) drugs. Advanced structural understanding of the stereo‐selective mode of action of DHP will facilitate drug discovery targeting Cav channels.