Identification of Verapamil Binding Sites Within Human Kv1.5 Channel Using Mutagenesis and Docking Simulation
| Autor: | Hiroshi Matsuura, Akiko Kojima, Wei-Guang Ding, Ayami Tano, Xinya Mi, Tomoyoshi Seto |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Physiology CHO Cells Molecular Docking Simulation lcsh:Physiology lcsh:Biochemistry 03 medical and health sciences Kv1.5 Potassium Channel 0302 clinical medicine Cricetulus Atrial Fibrillation medicine Potassium Channel Blockers Animals Humans Point Mutation lcsh:QD415-436 cardiovascular diseases Binding Sites lcsh:QP1-981 Chemistry Chinese hamster ovary cell Antagonist Effective refractory period Potassium channel blocker Electrophysiology 030104 developmental biology Amino Acid Substitution Verapamil Docking (molecular) 030220 oncology & carcinogenesis Biophysics cardiovascular system medicine.drug |
| Zdroj: | Cellular Physiology and Biochemistry, Vol 52, Iss 2, Pp 302-314 (2019) |
| ISSN: | 1421-9778 |
| Popis: | BACKGROUND/AIMS:The phenylalkylamine class of L-type Ca2+ channel antagonist verapamil prolongs the effective refractory period (ERP) of human atrium, which appears to contribute to the efficacy of verapamil in preventing reentrant-based atrial arrhythmias including atrial fibrillation. This study was designed to investigate the molecular and electrophysiological mechanism underlying the action of verapamil on human Kv1.5 (hKv1.5) channel that determines action potential duration and ERP in human atrium. METHODS:Site-directed mutagenesis created 10 single-point mutations within pore region of hKv1.5 channel. Wholecell patch-clamp method investigated the effect of verapamil on wild-type and mutant hKv1.5 channels heterologously expressed in Chinese hamster ovary cells. Docking simulation was conducted using open-state homology model of hKv1.5 channel pore. RESULTS:Verapamil preferentially blocked hKv1.5 channel in its open state with IC50 of 2.4±0.6 μM (n = 6). The blocking effect of verapamil was significantly attenuated in T479A, T480A, I502A, V505A, I508A, L510A, V512A and V516A mutants, compared with wild-type hKv1.5 channel. Computer docking simulation predicted that verapamil is positioned within central cavity of channel pore and has contact with Thr479, Thr480, Val505, Ile508, Ala509, Val512, Pro513 and Val516. CONCLUSION:Verapamil acts as an open-channel blocker of hKv1.5 channel, presumably due to direct binding to specific amino acids within pore region of hKv1.5 channel, such as Thr479, Thr480, Val505, Ile508, Val512 and Val516. This blocking effect of verapamil on hKv1.5 channel appears to contribute at least partly to prolongation of atrial ERP and resultant antiarrhythmic action on atrial fibrillation in humans. |
| Databáze: | OpenAIRE |
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