Using the DUMAS (Dual acquisition Magic Angle Spinning) solid-state NMR approach, we created new pulse schemes that enable the simultaneous acquisition of three dimensional (3D) experiments on uniformly 13C, 15N labeled proteins. These new experiments exploit the simultaneous cross-polarization (SIM-CP) from 1H to 13C and 15N to acquire two 3D experiments simultaneously. This is made possible by bidirectional polarization transfer between 13C and 15N and the long living 15N z-polarization in solid state NMR. To demonstrate the power of this approach, four 3D pulse sequences (NCACX, CANCO, NCOCX, CON(CA)CX) are combined into two pulse sequences (3D DUMAS-NCACX-CANCO, 3D DUMAS-NCOCX-CON(CA)CX) that allow simultaneous acquisition of these experiments, reducing the experimental time by approximately half. Importantly, the 3D DUMAS-NCACX-CANCO experiment alone makes it possible to obtain the majority of the backbone sequential resonance assignments for microcrystalline U-13C,15N ubiquitin. The DUMAS approach is general and applicable to many 3D experiments, nearly doubling the performance of NMR spectrometers.
Bibliographical noteFunding Information:
This work is supported by the National Institute of Health (GM 64742 and GM 72701). The authors would like to thank Dave Rice (Agilent), Dr. Frank Delaglio (NMRPipe) for helpful discussions, and to Fa-An Chao for preparation of the microcrystalline ubiquitin. 2D and 3D DUMAS pulse sequences are available for download at www.chem.umn.edu/groups/veglia .
- 3D DUMAS-NCACX-CANCO
- 3D DUMAS-NCOCX-CON(CA)CX
- DUMAS ssNMR
- Dual acquisition magic angle spinning
- Microcrystalline ubiquitin
- Solid-state NMR