Table 6.

Average R_{2 eff} values with optimized correlation times (τ_ex) and p_a for select terminal Asn and Gln ¹⁵N side chain resonances^a, ^b, ^c, ^d

	No TRTK-12			+ TRTK-12
	R2 eff AVE (s−1)	pa	τex (10−3 s)	R2 eff AVG (s−1)	pa	τex (10−3 s)
S100B
Asn37	18.8 ± 0.48	0.97 ± 0.01	2.00 ± 0.65	21.1 ± 0.23	NE	NE
Asn38	13.6 ± 1.33	NE	NE	16.6 ± 2.34	NE	NE
Gln50	11.3 ± 0.16	0.97 ± 0.01	3.66 ± 1.51	13.6 ± 0.18	0.73 ± 0.20	73 ± 60
D61NS100B
Asn37	11.7 ± 0.43	0.98 ± 0.02	29 ± 6.20	19.2 ± 2.06	NE	NE
Asn38	9.76 ± 0.65	NE	NE	11.6 ± 1.56	NE	NE
Gln50	5.85 ± 0.03	-	-	10.3 ± 0.17	0.98 ± 0.003	3.78 ± 0.29
Asn61	11.6 ± 0.75	0.98 ± 0.01	4.69 ± 1.33	28.0 ± 1.81	0.97 ± 0.03	0.13 ± 0.09
D63NS100B
Asn37	14.7 ± 0.09	0.97 ± 0.02	5.56 ± 2.53	17.8 ± 0.64	NE	NE
Asn38	11.7 ± 0.27	NE	NE	15.3 ± 0.79	NE	NE
Gln50	9.82 ± 0.07	0.94 ± 0.04	5.30 ± 4.42	10.8 ± 0.08	0.98 ± 0.01	62 ± 5.9
Asn63	19.0 ± 1.88	0.76 ± 0.16	57.5 ± 39	21.4 ± 1.29	NE	NE
D65NS100B
Asn37	EB	EB	EB	20.8 ± 0.71	NE	NE
Asn38	16.0 ± 1.25	0.93 ± 0.06	2.06 ± 1.31	12.2 ± 1.79	NE	NE
Gln50	13.6 ± 0.94	0.91 ± 0.03	36.5 ± 6.5	10.9 ± 0.08	NE	NE
Asn65	EB	EB	EB	EB	EB	EB

^aThe average (AVE) and RMSD values for R_{2 eff} are given for 14.1 T.

^bτ_ex and p_a was obtained by independently fitting the R_{2 eff} data from both proton amide resonances from the side chains of Asn and Gln using a two-site exchange model²⁸. The average values of the exchange parameters are reported together with the standard error estimated from the values obtained from the two proton side chain correlations.

^cNE = no exchange detected and EB = exchange broadened.

^dAlthough the R_{2 eff AVE} is not exclusively the result of ¹⁵N R₂ relaxation since ¹H Z-relaxation is also present (< 1%) during the CPMG period, R_{2 eff AVE} is provided here to show an overall change in R₂.