Table 1. Secondary structure composition of WT, N15S and P23H before and after H/D exchange as obtained from FTIR spectra (Fig 4).

The root mean squared deviation of both the H₂O and D₂O datasets from x-ray data estimates 9% total uncertainty.

Secondary Structure Details (in %)	STRIDE	WT_PBS		N15S_PBS		P23H_PBS
	PDB 1L9H	H20	D20	H20	D20	H20	D20
α-Helix	64	63	59	42	48	32	33
β-sheet	3	16	12	25	18	10	30
Random coil	12	12	19	21	15	52	24
β-Turns	22	9	10	12	19	6	13
	RMSD from PDB	9	9	17	11	27	22