Figure 1.

Pulse sequence for simultaneous measurement of the steady state {¹H}-¹⁵N NOE and the ¹⁵N R₁ relaxation rate constant. Thin and thick solid bars represent high-power 90° and 180° pulses, respectively; short open shapes represent water-selective 90° sinc pulses; short thin solid bars represent rectangular water-selective 90° pulses; thick solid bars flanked by two thin bars indicate a 90_x-210_y-90_x composite pulse; and the open shaped pulses during the T = n(2Δ – τ₁₈₀) relaxation period are cosine-modulated I-BURP2 180° pulses of length τ₁₈₀ crafted to leave the water magnetization unperturbed while maximizing inversion of amide protons. Delays: t_recycle = 11 s, Δ = 11 ms, δ = τ = 2.65 ms, γ = δ – ε/2, and ε > g6. Gradients were applied as square pulses. Gradients g1 and g6 were used for coherence selection and other gradients are used for artifact suppression. Gradients: g1 (600 μs, 21.7 G/cm), g2 (300 μs, 6.8 G/cm), g3 (1000 μs, 32.9 G/cm), g4 (500 μs, 6.8 G/cm), g5 (1000 μs, 13.2 G/cm), g6 (121.60 μs, 21.7 G/cm). All pulses are x-phase unless indicated. Phase cycling: ϕ₁ = y; ϕ₂ = y, −y, and ϕ_rec = y, −y. The phase ϕ₃ = y for I₋(0) and −x for I₊(0) in the R₁ experiment. Echo-antiecho selection is obtained by inverting g1 and ϕ₁. Pulse sequence and acquisition parameter files are provided as Online Resource 1 and 2, respectively