title: Studying enzyme mechanism by 13C nuclear magnetic resonance.
abstract: High-resolution carbon-13 nuclear magnetic resonance (NMR) spectra of enzyme-inhibitor and enzyme-substrate complexes provide detailed structural and stereochemical information on the mechanism of enzyme action. The proteases trypsin and papain are shown to form tetrahedrally coordinated complexes and acyl derivatives with a variety of compounds artificially enriched at the site or sites of interest. These results are compared with the structural information derived from x-ray diffraction. Detailed NMR studies have provided a clearer picture of the ionization state of the residues participating in enzyme-catalyzed processes than other more classical techniques. The dynamics of enzymic catalysis can be observed at sub-zero temperatures by a combination of cryoenzymology and carbon-13 NMR spectroscopy. With these powerful techniques, transient, covalently bound intermediates in enzyme-catalyzed reactions can be detected and their structures rigorously assigned.
mesh_terms: D001665:Binding Sites; D002247:Carbon Isotopes; D002268:Carboxypeptidases / Q000378:metabolism; D043422:Carboxypeptidases A; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D003067:Coenzymes / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism; D004798:Enzymes / Q000378:metabolism*; D005615:Freezing; D005634:Fructose-Bisphosphate Aldolase / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D010206:Papain / Q000378:metabolism; D010434:Pepsin A / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D011480:Protease Inhibitors; D011622:Pterins / Q000378:metabolism; D011732:Pyridoxal Phosphate / Q000378:metabolism; D012697:Serine Endopeptidases
chemical_list: D002247:Carbon Isotopes; D003067:Coenzymes; D004798:Enzymes; D011480:Protease Inhibitors; D011622:Pterins; C011552:tetrahydropterin; D011732:Pyridoxal Phosphate; D002268:Carboxypeptidases; D010450:Endopeptidases; D010447:Peptide Hydrolases; D043422:Carboxypeptidases A; D012697:Serine Endopeptidases; D010206:Papain; D010434:Pepsin A; D005634:Fructose-Bisphosphate Aldolase