title: Modeling the binding modes of Kv1.5 potassium channel and blockers.
abstract: The ultra-rapid delayed rectifier potassium current (I(Kur)), encoded by Kv1.5 gene, is the critical determinant of Phase I repolarization of action potential duration (APD). The evidences that Kv1.5 gene expresses more extensively in human atrial myocytes than in ventricle and the I(Kur) currents has not been recorded in the human ventricle, suggest Kv1.5 potassium channel as a selective target for the treatment of atrial fibrillation (AF). Recent mutagenesis studies have provided us some evidences that are useful in designing Kv1.5 blockers. In order to further evaluate these molecular biological information, the homology model of Kv1.5 potassium channel was established based on the Kv1.2 crystal structure (PDB entry: 2A79) using MODELLER 9v2 program. After the molecular dynamics refinement, the optimized homology model was assessed as a reliable structure by PROCHECK, ERRAT, WHAT-IF, PROSA2003 and DOPE graph. The results of molecular docking studies on different Kv1.5 inhibitors are in agreement with the published mutagenesis data. Based on the docking conformations, a pharmacophore model was developed by HipHop algorithm in order to probe the common features of blockers. By analyzing the results, active site architecture, certain key residues and pharmacophore common-features that are responsible for substrate specificity were identified on the Kv1.5 potassium channel, which would be very helpful in understanding the blockade mechanism of Kv1.5 potassium channel and providing insights into rational design of novel Kv1.5 blockers.
authors.affiliation: Department of Medicinal Chemistry, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yang
authors.forename: Lupei
authors.initials: L
authors.lastname: Du
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Wang
authors.forename: Minyong
authors.initials: M
authors.lastname: Li
authors.forename: Qidong
authors.initials: Q
authors.lastname: You
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain / Q000502:physiology; D006801:Humans; D051666:Kv1.5 Potassium Channel / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism*; D008956:Models, Chemical; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D017386:Sequence Homology, Amino Acid
chemical_list: C496981:KCNA5 protein, human; D051666:Kv1.5 Potassium Channel; D026902:Potassium Channel Blockers; D011188:Potassium