Purification and structural characterization of the voltage-sensor domain of the hERG potassium channel

► The voltage-sensor domain (VSD) of hERG potassium channel was over-expressed in Escherichia coli and purified in LMPG micelles. ► Purified VSD in LMPG micelles adopts α-helical structures. ► Assignments for S3 and S4 of VSD indicate the presence of helical structures.