A C-terminally amidated analogue of ShK is a potent and selective blocker of the voltage-gated potassium channel Kv1.3

• Published in: FEBS letters Vol. 586; no. 22; pp. 3996 - 4001
• Main Authors: Pennington, Michael W., Harunur Rashid, M., Tajhya, Rajeev B., Beeton, Christine, Kuyucak, Serdar, Norton, Raymond S.
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 16.11.2012
• Subjects: Algorithms; Amides - chemistry; Animals; Binding Sites; Binding, Competitive; C-terminal amide; C-terminally amidated ShK; Cell Line, Tumor; Cell Proliferation - drug effects; Cells, Cultured; Cnidarian Venoms - chemistry; Cnidarian Venoms - metabolism; Cnidarian Venoms - pharmacology; Dose-Response Relationship, Drug; effector memory T-cells; Electrophysiology; Humans; Ion Channel Gating - drug effects; Ion Channel Gating - genetics; Ion Channel Gating - physiology; K+ channel toxin from Stichodactyla helianthus; Kv1.1 Potassium Channel - genetics; Kv1.1 Potassium Channel - metabolism; Kv1.1 Potassium Channel - physiology; Kv1.3 Potassium Channel - genetics; Kv1.3 Potassium Channel - metabolism; Kv1.3 Potassium Channel - physiology; Mice; Models, Molecular; molecular dynamics; Molecular Dynamics Simulation; Patch-Clamp Techniques; PMF; Potassium channel; Potassium Channel Blockers - chemistry; Potassium Channel Blockers - metabolism; Potassium Channel Blockers - pharmacology; Potential of mean force; Protein Binding; Protein Structure, Tertiary; ShK; ShK with a C-terminal Lys and amide; ShK-amide; ShK-K-amide; T-Lymphocytes - cytology; T-Lymphocytes - drug effects; TEM; Umbrella sampling; voltage-gated K+ channel; ShK-K-amide; ShK-amide; Umbrella sampling; ShK; MD; PMF; Electrophysiology; Potential of mean force; Kv; TEM; Potassium channel; C-terminal amide
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/j.febslet.2012.09.038

► ShK is a potent blocker of potassium channels. ► A new ShK analogue with a C-terminal Lys residue and amide was designed. ► ShK-K-amide is a potent and selective blocker of Kv1.3. ► ShK-K-amide was docked with models of Kv1.3 and Kv1.1. ► Umbrella sampling simulations were used to calculate binding free energies. ShK, a 35-residue peptide from a sea anemone, is a potent blocker of potassium channels. Here we describe a new ShK analogue with an additional C-terminus Lys residue and amide. ShK-K-amide is a potent blocker of Kv1.3 and, in contrast to ShK and ShK-amide, is selective for Kv1.3. To understand this selectivity, we created complexes of ShK-K-amide with Kv1.3 and Kv1.1 using docking and molecular dynamics simulations, then performed umbrella sampling simulations to construct the potential of mean force of the ligand and calculate the corresponding binding free energy for the most stable configuration. The results agree well with experimental data.