生物大分子波谱学原理 吴季辉 A Strategy for Elucidating the Structure of Peptides/Proteins Using 2D Proton Homonuclear NMR Experiments Obtain primary sequence of peptide/protein Collect 2D NMR spectra H-H DQF-COSY H-IH TOCSY,short and long mixing times H-H NOESY,short and long mixing times Assign spin systems use TOCSY and DQF-COSY spectra and,if necessary,NOESY spectra Assign sequential amino acids use NOESY HN-HN and HN-Ha regions Obtain structural information from NMR spectra NOESY cross peak intensities H班 DQF-COSY 3JHN-Ha φ PE COSY 3JHa-H邱 Z H20/D20 exch. HN exchange rates h-bonds Generate structure Use software that "folds"primary sequence on basis of structural info Visualize structures using molecular graphics Refine structure,if needed,with additional data生物大分子波谱学原理 吴季辉