title: Protein carbon-13 spin systems by a single two-dimensional nuclear magnetic resonance experiment.
abstract: By applying a two-dimensional double-quantum carbon-13 nuclear magnetic resonance experiment to a protein uniformly enriched to 26 percent carbon-13, networks of directly bonded carbon atoms were identified by virtue of their one-bond spin-spin couplings and were classified by amino acid type according to their particular single- and double-quantum chemical shift patterns. Spin systems of 75 of the 98 amino acid residues in a protein, oxidized Anabaena 7120 ferredoxin (molecular weight 11,000), were identified by this approach, which represents a key step in an improved methodology for assigning protein nuclear magnetic resonance spectra. Missing spin systems corresponded primarily to residues located adjacent to the paramagnetic iron-sulfur cluster.
mesh_terms: D000596:Amino Acids; D002247:Carbon Isotopes; D000458:Cyanobacteria / Q000032:analysis; D005288:Ferredoxins; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D013057:Spectrum Analysis
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D005288:Ferredoxins