Table 1.

Spatial location and free energy of opening to HX, in the absence of denaturant, for the measured amide protons of Trx

Residue	Structure	% Surface	H-bond	kint (h−1)a	ΔGop
Class I
Phe 12	helix 1	0	8 Thr O	36165	6.4
Val 16	helix 1	4.4	12 Phe O	4150	4.7
Lys 18	helix 1	15.7	—	30783	6.1
Lys 36	helix 2	25.2	33 Gly O	177134	7.5
Ala 46	helix 2	7.1	42 leu O	32223	7.0
Leu 103	helix 4	0	99 Leu O	16531	8.8
Asp 104	helix 4	17.5	100 Lys O	16916	7.1
Class II
Ile 23	β strand 2	0	81 Phe O	10191	9.1
Leu 24	β strand 2	0	54 Thr O	8478	9.3
Asp 26	β strand 2	0.1	56 Ala O	19875	7.9
Phe 27	β strand 2	0	77 Thr O	20811	9.6
Trp 28	β strand 2	0	58 Leu O	8478	9.2
Ala 29	β strand 2	0	—	42490	8.7
Thr 54	β strand 3	0	—	28724	7.8
Val 55	β strand 3	5.2	—	17308	9.8
Ala 56	β strand 3	0	24 Leu O	39654	10.0
Leu 58	β strand 3	0	26 Asp O	18979	6.6
Ile 60	β strand 3	16	28 Trp O	21297	9.5
Leu 78	β strand 4	0	90 Lys O	22820	7.3
Leu 79	β strand 4	0	25 Val O	8877	9.0
Leu 80	β strand 4	0	88 Ala O	8877	9.2
Phe 81	β strand 4	0.6	23 Ile O	19422	9.8
Ile 41	helix 2	0	—	5864	5.6
Leu 42	helix 2	0	38 Ile O	8478	6.1

^a Values of k_int were determined from model-peptide data, as described by Bai et al. 1993.