The interhelical angle was defined as the supplement of the angle between helix A (TnC 14-25) and helix B (TnC 38-47) of Troponin C, similar to the convention used in previous literature . The endpoints of the helix vector were calculated by taking the average of the coordinates of ten alpha carbons from each end of the helix. A Python reimplementation of Interhlx (K. Yap, University of Toronto) was used for A-B angle calculations.