title: Paramagnetic NMR study of Cu(2+)-IDA complex localization on a protein surface and its application to elucidate long distance information.
abstract: The paramagnetic metal chelate complex Cu(2+)-iminodiacetic acid (Cu(2+)-IDA) was mixed with ubiquitin, a small globular protein. Quantitative analyses of (1)H and (15)N chemical shift changes and line broadenings induced by the paramagnetic effects indicated that Cu(2+)-IDA was localized to a histidine residue (His68) on the ubiquitin surface. The distances between the backbone amide proton and the Cu(2+) relaxation center were evaluated from the proton transverse relaxation rates enhanced by the paramagnetic effect. These correlated well with the distances calculated from the crystal structure up to 20 A. Here, we show that a Cu(2+)-IDA is the first paramagnetic reagent that specifically localizes to a histidine residue on the protein surface and gives the long-range distance information.
authors.affiliation: Laboratory of Biophysics, Graduate School of Biological Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Nomura
authors.forename: Toshitatsu
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Kohno
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Fujiwara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tenno
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shirakawa
authors.forename: Itsuko
authors.initials: I
authors.lastname: Ishizaki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Matsuyama
authors.forename: Masaki
authors.initials: M
authors.lastname: Mishima
authors.forename: Chojiro
authors.initials: C
authors.lastname: Kojima
mesh_terms: D000577:Amides / Q000737:chemistry; D000595:Amino Acid Sequence; D003300:Copper / Q000737:chemistry* / Q000378:metabolism; D006639:Histidine / Q000737:chemistry; D006801:Humans; D007098:Imino Acids / Q000737:chemistry* / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D025801:Ubiquitin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D000577:Amides; D007098:Imino Acids; D011994:Recombinant Proteins; D025801:Ubiquitin; D006639:Histidine; D003300:Copper; C008109:iminodiacetic acid