A schematic representation of the non-native subsystems created for the MD simulations. (A-D) show the relevant single disulfide bond maintained for each subsystem colored in blue (C94-C76), orange (C80-C64), pink (C30-C115), and red (C6-C127), respectively, with the labels denoting the cysteine residues involved in the disulfide bond. (E) shows the two sub-states based on pH and with all reduced disulfide bonds, with the rotationally degenerate GLU35 highlighted in purple for State 1 and State 2.