{"id":19594,"date":"2026-06-17T10:24:25","date_gmt":"2026-06-17T08:24:25","guid":{"rendered":"https:\/\/www.nanion.de\/?post_type=resource_library&#038;p=19594"},"modified":"2026-06-17T10:24:25","modified_gmt":"2026-06-17T08:24:25","slug":"2026-structural-determinants-of-tricyclic-antidepressant-engagement-of-human-cav3-channels","status":"publish","type":"resource_library","link":"https:\/\/nanion.com\/ja\/resource_library\/2026-structural-determinants-of-tricyclic-antidepressant-engagement-of-human-cav3-channels\/","title":{"rendered":"2026 &#8211; Structural Determinants of Tricyclic Antidepressant Engagement of Human CaV3 Channels"},"content":{"rendered":"<p><b>Background and Purpose<\/b> Tricyclic antidepressants (TCAs) exhibit clinically relevant polypharmacology and interact with multiple molecular targets, including voltage\u2011gated calcium channels. Although inhibition of Ca<sub>V<\/sub>3 and Ca<sub>V<\/sub>2 channels has been reported, the molecular determinants underlying these interactions remain unclear. This study examined how TCAs interact with Ca<sub>V<\/sub>3 channels relative to Ca<sub>V<\/sub>2 channels at the channel\u2011family level. <b>Experimental Approach<\/b> Automated planar patch\u2011clamp electrophysiology was used to assess inhibition by amitriptyline, desipramine, nortriptyline, and trimipramine across multiple Ca<sub>V<\/sub>3 and Ca<sub>V<\/sub>2 channel isoforms under standardised recording conditions. Amitriptyline and trimipramine were selected for detailed mechanistic analysis at Ca<sub>V<\/sub>3.3 and Ca<sub>V<\/sub>2.2 channels. Molecular docking and molecular dynamics simulations were combined with targeted alanine mutagenesis to identify and functionally evaluate pore\u2011adjacent features associated with TCA sensitivity. <b>Key Results<\/b> TCAs inhibited both Ca<sub>V<\/sub>3 and Ca<sub>V<\/sub>2 channels within the micromolar concentration range, with lower apparent inhibitory thresholds for Ca<sub>V<\/sub>3 channels. Structural modelling identified pore\u2011adjacent regions near a conserved Ca<sub>V<\/sub>3 cysteine (C393 in Ca<sub>V<\/sub>3.3) where ligand proximity differed between compounds during simulations. No comparable features were identified at the corresponding region of Ca<sub>V<\/sub>2 channels. Alanine substitution produced compound\u2011dependent effects, with amitriptyline showing greater sensitivity to C393 substitution than trimipramine. Mutant\u2011specific analyses also revealed greater variability in substitution effects for amitriptyline. <b>Conclusions and Implications<\/b> These findings identify channel\u2011family\u2011specific structural features associated with differential TCA engagement of Ca<sub>V<\/sub>3 channels, whereas Ca<sub>V<\/sub>2 inhibition appears consistent with more distributed cavity interactions. Collectively, the results refine understanding of tricyclic polypharmacology by placing calcium channel modulation within a mechanistic framework.<\/p>\n","protected":false},"featured_media":0,"template":"","products_tags":[42],"resource_type":[75],"application_areas":[50,53],"therapeutic_areas":[55,143],"target_categories":[61],"target_families":[340],"targets":[],"resource_keyword":[],"class_list":["post-19594","resource_library","type-resource_library","status-publish","hentry","products_tags-syncropatch-384","resource_type-publication","application_areas-ion-channels","application_areas-assay-development-and-validation","therapeutic_areas-cns","therapeutic_areas-assay-development-and-validation","target_categories-voltage-gated-ion-channels","target_families-cav-channels"],"acf":[],"_links":{"self":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_library\/19594","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_library"}],"about":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/types\/resource_library"}],"wp:attachment":[{"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/media?parent=19594"}],"wp:term":[{"taxonomy":"products_tags","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/products_tags?post=19594"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_type?post=19594"},{"taxonomy":"application_areas","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/application_areas?post=19594"},{"taxonomy":"therapeutic_areas","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/therapeutic_areas?post=19594"},{"taxonomy":"target_categories","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/target_categories?post=19594"},{"taxonomy":"target_families","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/target_families?post=19594"},{"taxonomy":"targets","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/targets?post=19594"},{"taxonomy":"resource_keyword","embeddable":true,"href":"https:\/\/nanion.com\/ja\/wp-json\/wp\/v2\/resource_keyword?post=19594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}