Table 1.

Comparison of ¹⁵N relaxation parameters measured with the previous and current pulse sequences ^a. Shown below are data for the Lys side-chain NH₃⁺ groups in the complex of ¹⁵N-labeled Antp homeodomain and unlabeled 15-bp DNA containing a phosphorodithioate at the K46 interaction site.

Parameters	K46	K55	K57	K58
15N R1 (s−1) b	1.093 ± 0.013	0.637 ± 0.005	1.035 ± 0.004	0.363 ± 0.002
15N R1 (s−1) c	1.081 ± 0.023	0.617 ± 0.008	1.037 ± 0.008	0.364 ± 0.003
15N R2,ini (s−1) b	2.55 ± 0.10	1.76 ± 0.07	2.95 ± 0.04	1.20 ± 0.03
15N R2,ini (s−1) c	2.74 ± 0.20	2.05 ± 0.12	2.76 ± 0.06	1.14 ± 0.06
Heteronuclear NOE b	−2.44 ± 0.12	−2.83 ± 0.10	−2.54 ± 0.05	−2.71 ± 0.05
Heteronuclear NOE c	−2.53 ± 0.18	−2.75 ± 0.13	−2.60 ± 0.08	−2.65 ± 0.07

^a The experiments were conducted at 15 °C and the ¹H frequency of 750 MHz. Uncertainties were estimated using the Monte Carlo approach based on the noise standard deviation of the spectra. ^b Measured with the current pulse sequences shown in Figure 1. ^c Measured with the previous pulse sequences [15].