TABLE 1.

Analysis of residues with significant exchange broadening

Residue*	ΔRex* (s−1)	ΔΔRex†(s−1)	Rex* (s−1)	(μs)*	(ppm)*	f†
14	<0.7	−2.3	4.5	<33	1.5	<0.5
19	3.4	−3.6	12.0	55	2.8	0.6
27	1.6	0.0	8.6	40	2.8	0.8
28	2.0	1.1	7.2	55	2.2	0.9
36	2.2	1.6	1	>220	<0.8	–
39	4.7	1.5	23.8	40	4.6	0.9
42	4.2	−1.0	1.7	>210	<0.9	–
51	0.5	−1.5	2.8	37	1.2	0.5
55	6.2	−7.8	28.0	45	4.6	0.6
57	2.9	1.45	1	>230	<0.8	–
60	3.3	−0.1	5.8	90	1.7	0.8
72	2.3	−0.0	10.0	20	2.8	0.8
73	2.2	0.4	7.9	62	2.3	0.9
75	1.6	−0.3	6.5	50	2.2	0.8
76	0.6	−8.9	11.0	15	5.0	0.4
77	1.9	0.7	8.5	45	2.6	0.8
92	2.2	−1.1	8.3	55	2.4	0.7
112	3.4	1.7	8.0	70	2.2	0.9
113	3.2	1.2	9.5	60	2.4	0.9
115	4.6	1.2	1	>300	<1.1	–
118	<0.7	−2.0	3.3	<35	1.4	<0.5
142	–	–	20.3	–	–	–
144	0.8	0.5	8.0	20	3.6	0.8
146	5.8	–0.7	9.9	90	2.2	0.8
147	2.7	1.7	2.2	145	1	0.9

^*Selected residues (selection value underlined) with either R_ex > 6.4 s⁻¹ or ΔR_ex > 2.5 s⁻¹ or ΔΔR_ex < −1.4 s⁻¹. The fast exchange equations were used to derive from the correlation of ΔR_ex and R_ex as explained in the Theory section. The error in is estimated to be ∼30 μs and ∼1 ppm in based on 1 s⁻¹ errors in ΔR_ex and R_ex; is calculated from with p_A = p_B = 0.5 and represents the minimum value of Δ_ex, because p_Ap_B reaches a maximum at p_A = 0.5. The ΔR_ex showed a systematic offset of ∼−2 s⁻¹. The values given and used in the derivation of and have been corrected for this offset. Residues 36, 42, 57, and 115 have small R_ex; the is a lower limit and the an upper limit based on a maximum value of R_ex of 1 s⁻¹.

^†Residues 14, 19, 51, 55, 76, 92, 118, and 146 show a relatively high decrease in ΔR_ex (ΔΔR_ex < −0.5, italic) upon decrease in temperature, leading to relatively large fractional decrease in the exchange rate k_ex (f = k_ex,300/k_ex,308, italic; see Theory section for the equations used). Based on the error in ΔΔR_ex (1.4 s⁻¹) and ΔR_ex (0.7 s⁻¹), the error in f is estimated to be 0.15. For the four residues 36, 42, 57, and 115, no reliable estimate of f can be made, because of the uncertainty in the value of k_ex. For residues 14 and 118 the upper limit of f and is given as estimated from the lower limit of ΔR_ex.