AUT1 (AUT-1) is a novel specific modulator of Kv3 channels (EC50: 4.7 and 4.9 uM for Kv3.1b and Kv3.2a).

Kv3.1b channel:4.7 μM, Kv3.2a channel:4.9 μM

The population patch-clamp mode of an automated voltage clamp recording with IonWorks Quattro was used. Briefly, the effects on these channels were tested using 384-well population patch-clamp plates. Seal resistance was measured for each well, and cells were perforated by incubation with 100 mg/ml amphotericin B. Cells were held at 270 mV and stepped to 215 mV for 100 milliseconds (partial channel activation), and after 100 milliseconds at 270 mV, a second pulse to 140 mV was applied for 50 milliseconds (full channel activation). In all of the experiments, this voltage protocol was applied to cells before and following a 3-minute incubation with AUT1. 1-Cyclohexyl-1-[(7,8-dimethyl-2-oxo-1H-quinolin-3-yl)methyl]-3-phenylurea (10 mM), which we had previously found to be a potent and full activator of human Kv3.1 and Kv3.2 channels, was included in all assays as a standard. An external buffer with the addition of dimethyl sulfoxide (DMSO) was also tested to provide a vehicle baseline. Recordings were performed in the following buffers: Dulbecco's phosphate-buffered saline (PBS) with MgCl2 and CaCl2 as an extracellular solution and 50 mM KCl, 100 mM K-gluconate, 3.2 mM MgCl2, and 5 mM HEPES, pH 7.3 adjusted with KOH, as an intracellular solution. An online correction of 115–20 mV was applied to correct for junction potentials. The current signal was sampled at 10 kHz [1].

DMSO: 250 mg/mL (732.36 mM), Sonication is recommended.

10% DMSO+40% PEG300+5% Tween 80+45% Saline: 5 mg/mL (14.65 mM), Sonication is recommended.