SOLUTION NMR Experimental Data


Experimental Details
Sample Conditions
Sample Contents0.8mM IL21 U-15N, 20mM phosphate, 50mM NaCl, 1mM NaN3
Solvent90% H2O/10% D2O
Ionic Strength50mM NaCl
pH5.5
Pressureambient
Temperature (K)300
Experiment(s):3D_15N-separated_NOESY, HNHA
Sample Contents0.8mM IL21 U-15N,13C, 20mM phosphate, 50mM NaCl, 1mM NaN3
Solvent100% D2O
Ionic Strength50mM NaCl
pH5.5
Pressureambient
Temperature (K)300
Experiment(s):3D_13C-separated_NOESY, 2D NOESY
Spectrometer Information
Manufacturer Model Field Strength
Bruker AV 600.0
Varian INOVA 800.0
NMR Refinement
Method simulated annealing
Details A total of 1235, 2994 and 449 peaks from 15N-separated, 13C-separated NOESY and 2D NOESY spectra, respectively, were included in structure calculations. Together with chemical shifts for the assigned resonances, the NOEs were analyzed with Cyana using the candid protocol for automatic NOE assignment and structure calculation. Additional sources of structural information were included in the calculations. Thus two disulfide bonds were enforced between Cys43 and Cys94, and between Cys50 and Cys97. This disulfide pattern has been established for the hIL-21 molecule through an analysis which combined protease cleavage, Edman degradation, and MS. Test calculations without disulfide bond constraints supported this pattern. Chemical shift values for HA, CA, CB, N and CO atoms were analyzed to predict phi and psi backbone angles using the computer program Talos. Talos gave good predictions for 78 residues, and 156 angle phi/psi angle constraints were included in the calculations with an uncertainty of 30 degrees. From the HNHA spectrum 72 J(HA-HN) scalar coupling constants were extracted and included in the structure calculations. Hydrogen bond constraints were added for 20 backbone amide protons which exchange slowly in deuterium exchange experiments. Hydrogen bond patterns were identified based on structures calculated without hydrogen bond constraints.
NMR Ensemble Information
Conformer Selection Criteria structures with the lowest energy
Conformers Calculated Total Number 64
Conformers Submitted Total Number 20
Representative Model Choice Rationale
1 lowest energy
Additional NMR Experimental Information
1 The structure was determined using triple-resonance NMR spectroscopy.
Computation: NMR Software
# Classification Software Name Author
1 refinement version: 1.0.8 CYANA Guntert P.
2 data analysis Talos Cornilescu G., Delaglio F., Bax A.
3 data analysis version: 3.110 sparky Goddard T.D., Kneller D.G.
4 processing version: 2004 FELIX Accelrys
5 collection version: 3.5 XWINNMR Bruker