title: An efficient NMR approach for obtaining sequence-specific resonance assignments of larger proteins based on multiple isotopic labeling.
abstract: By simultaneously incorporating in a protein 13C-carbonyl- and 15N-labeled amino acids with different levels of enrichment, characteristics asymmetric doublet-like patterns are observed for 15N nuclei that are directly adjacent to the 13C1-labeled residues, providing unambiguous identification of a large number of unique dipeptide fragments of the protein. Additional assignments and qualitative structural information can be obtained from such a selectively labeled protein by recording multiple bond correlation spectra. The procedure is demonstrated for the protein calmodulin, complexed with calcium.
authors.affiliation: Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, MD 20892.
authors.forename: M
authors.initials: M
authors.lastname: Ikura
authors.forename: M
authors.initials: M
authors.lastname: Krinks
authors.forename: D A
authors.initials: DA
authors.lastname: Torchia
authors.forename: A
authors.initials: A
authors.lastname: Bax
mesh_terms: D000818:Animals; D002147:Calmodulin; D004331:Drosophila melanogaster; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D011487:Protein Conformation; D011994:Recombinant Proteins
chemical_list: D002147:Calmodulin; D011994:Recombinant Proteins