Original ArticleInteractions of Propofol With Human Voltage-gated Kv1.5 Channel Determined by Docking Simulation and Mutagenesis AnalysesKojima, Akiko MD, PhD*; Fukushima, Yutaka MD*; Ito, Yuki MD*; Ding, Wei-Guang MD, PhD†; Ueda, Rika MSc†; Seto, Tomoyoshi MSc, MD, PhD*; Kitagawa, Hirotoshi MD, PhD*; Matsuura, Hiroshi MD, PhD†Author Information Departments of *Anesthesiology; and †Physiology, Shiga University of Medical Science, Otsu, Shiga, Japan. Reprints: Akiko Kojima, MD, PhD, Department of Anesthesiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan (e-mail: [email protected]). Supported by Grants-in-Aid for Scientific Research (Nos. 26462336 and 17K11050 to A. Kojima and Nos. 25460287 and 17K08536 to H. Matsuura) from The Japan Society for the Promotion of Science (Tokyo, Japan). The authors report no conflicts of interest. Journal of Cardiovascular Pharmacology: January 2018 - Volume 71 - Issue 1 - p 10-18 doi: 10.1097/FJC.0000000000000538 Buy Metrics Abstract Propofol blocks the voltage-gated human Kv1.5 (hKv1.5) channel by preferentially affecting in its open state. A previous mutational study suggested that several amino acids within the pore region of the hKv1.5 channel are involved in mediating the blocking action of propofol. The present investigation was undertaken to elucidate the predicted binding modes of propofol within the pore cavity of the open-state hKv1.5 channel, using computational docking and mutagenesis approaches. The docking simulation using a homology model of the hKv1.5 channel, constructed based on the crystal structure of the Kv1.2 channel, predicted that propofol was positioned at the base of the pore cavity of hKv1.5 channel, adjacent to 4 amino acids Thr479, Thr480, Val505, and Ile508, and formed arene-H interactions with Val505. The patch-clamp experiments on wild-type and mutant hKv1.5 channels constructed by site-directed mutagenesis revealed that the blocking potency of propofol was significantly reduced in T480A, V505A, and I508A but not in T479A mutants compared with wild-type hKv1.5 channel. These computational docking and experimental mutational analyses suggest that propofol is positioned at the base of the pore cavity and forms functional contact with Thr480, Val505, and Ile508 to directly block the hKv1.5 channel. Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved.