SOLUTION NMR Experimental Data

Experimental Details
Sample Conditions
Sample Contents1.7mM PACAP21; 40mM PACAP receptor; 80mM phosphate buffer (pH 6.3)
Solvent90% H2O/10% D2O
Ionic Strength0.41
Temperature (K)298
Spectrometer Information
Manufacturer Model Field Strength
Bruker DRX 800.0
NMR Refinement
Method Iterative relaxation matrix analysis (IRMA) and simulated annealing (SA)
Details The structures are calculated by SA protocol of X-PLOR based on a total of 387 TRNOE-derived distance restraints obtained from the IRMA refinement.
NMR Ensemble Information
Conformer Selection Criteria structures with the lowest energy
Conformers Calculated Total Number 200
Conformers Submitted Total Number 25
Representative Model Choice Rationale
1 closest to the average
Additional NMR Experimental Information
1 Both TRNOE and NOE cross peaks were observed in the spectrum: the former reflects the conformation of PACAP21 in the receptor-bound form, while the latter reflects that of unbound PACAP21. Upon addition of a higher affinity ligand, PACAP27, the TRNOE cross peaks were selectively eliminated due to a competitive inhibition of the specific binding of PACAP21 to the receptor. Accordingly, the subtraction of these two spectra yields TRNOE-related cross peaks exclusively.
Computation: NMR Software
# Classification Software Name Author
1 structure solution version: 3.1 X-PLOR Brunger, A.T.
2 iterative matrix relaxation version: 30-Jul-90 IRMA Kaptein, R.
3 refinement version: 3.1 X-PLOR Brunger, A.T.