title: Toward the complete assignment of the carbon nuclear magnetic resonance spectrum of the basic pancreatic trypsin inhibitor.
abstract: A total of 54 of the 58 alpha-carbon resonances and numerous side-chain carbon signals were individually assigned in the basic pancreatic trypsin inhibitor by using two-dimensional heteronuclear correlated and relayed coherence transfer spectroscopy with proton detection. No isotope enrichment was used, and the spectra were recorded in 5-mm sample tubes. The pulse sequences were optimized to eliminate, prior to phase cycling, the signals of protons attached to 12C. We have concentrated on assignments of carbons bearing a single hydrogen in view of a relatively easy interpretation of carbon relaxation times, and most of these carbon resonances could be assigned. Furthermore, we demonstrate that two-dimensional heteronuclear correlated and relayed coherence transfer spectra can be used to elucidate connectivities between degenerate resonances within proton spin systems that often occur in threonines and aromatic side chains.
mesh_terms: D007611:Aprotinin; D002247:Carbon Isotopes; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D011487:Protein Conformation
chemical_list: D002247:Carbon Isotopes; D007611:Aprotinin