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. 2014 Aug 7;136(35):12489–12497. doi: 10.1021/ja507382j

Figure 3.

Figure 3

Pulse sequences for the six 1H-detected 13C–15N–1H 3D correlation experiments, with an illustration of the coherence transfers and spins involved: (a) inter-residue (H)CONH experiment (COi-1NiHi), (b) intraresidue (H)CO(CA)NH experiment (COiNiHi), (c) intraresidue (H)CANH experiment (CAiNiHi), (d) inter-residue (H)(CO)CA(CO)NH experiment (CAi-1NiHi), (e) intraresidue (H)(CA)CB(CA)NH experiment (CBiNiHi), and (f) inter-residue (H)(CA)CB(CACO)NH experiment (CBi-1NiHi). Narrow and broad black rectangles indicate π/2 and π pulses, respectively, and bell shapes represent selective inversion pulses. Orange boxes indicate cross-polarization, and gray boxes indicate heteronuclear decoupling. The MISSISSIPPI sequence is indicated by the striped box. Spin-echoes involved in the transfer between CO and CA are highlighted in blue and red, when the coherence is present on the CO and CA, respectively, and spin-echoes involved in transfer between CA and CB are highlighted in green. All pulses are of phases 0, unless indicated differently. (a and c) φ1 = 0 2, φ20 = 1, φ2 = 1, φ6 = 0 0 2 2, φ12 = 1, φ7 = 1, φ11 = {1}*4 {3}*4, φrec = 1 3 3 1 3 1 1 3; (b) φ1 = 0 2, φ20 = 1, φ2 = 1, φ6 = 0 0 2 2, φ12 = 1, φ7 = 1, φ11 = 1, φ14 = {0}*4 {1}*4, φ17 = {0}*8 {1}*8, φrec = 3 1 1 3 1 3 3 1 1 3 3 1 3 1 1 3; (d and e) φ1 = 1 3, φ2 = 1 1 3 3, φ4 = 1, φ5 = 1, φ7 = {1}*4 {3}*4, φ8 = {0}*8 {2}*8, φ9 = 3, φ10 = 1, φrec = 0 2 2 0 2 0 0 2 2 0 0 2 0 2 2 0; (f) φ1 = 1 3, φ2 = 1 1 3 3, φ4 = 1, φ5 = 1, φ6 = {0}*16 {2}*16, φ9 = 3, φ10 = 1, φ14 = {0}*8 {1}*8, φ16 = 3, φ17 = {0}*4 {1}*4, φrec = 0 2 2 0 2 0 0 2 2 0 0 2 0 2 2 0 2 0 0 2 0 2 2 0 0 2 2 0 2 0 0 2. Specific CP to or from 13C may require a frequency shift, and in this case, the phases of rf during the two 13C CP periods are aligned respectively at the end and at the beginning of the contact time. In the diagrams, filled circles denote spins for which the frequency of evolution is measured. Solid lines represent transfers between bonded nuclei and dashed lines between nonbonded nuclei.