title: 3-Mercapto-2,6-pyridinedicarboxylic acid: a small lanthanide-binding tag for protein studies by NMR spectroscopy.
abstract: Paramagnetic effects from lanthanide ions present powerful tools for protein studies by nuclear magnetic resonance (NMR) spectroscopy provided that the lanthanide can be site-specifically and rigidly attached to the protein. A new, particularly small and rigid lanthanide-binding tag, 3-mercapto-2,6-pyridinedicarboxylic acid (3MDPA), was synthesized and attached to two different proteins via a disulfide bond. The complexes of the N-terminal domain of the E. coli arginine repressor (ArgN) with seven different paramagnetic lanthanide ions and Co(2+) were analyzed in detail by NMR spectroscopy. The magnetic susceptibility anisotropy (Delta chi) tensors and metal position were determined from pseudocontact shifts. The 3MDPA tag generated very different Delta chi tensor orientations compared to the previously studied 4-mercaptomethyl-DPA tag, making it a highly complementary and useful tool for protein NMR studies.
authors.affiliation: School of Chemistry, University of New South Wales, Sydney NSW 2052, Australia.
authors.forename: Bradley
authors.initials: B
authors.lastname: Man
authors.forename: Xun-Cheng
authors.initials: XC
authors.lastname: Su
authors.forename: Haobo
authors.initials: H
authors.lastname: Liang
authors.forename: Shane
authors.initials: S
authors.lastname: Simonsen
authors.forename: Thomas
authors.initials: T
authors.lastname: Huber
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Messerle
authors.forename: Gottfried
authors.initials: G
authors.lastname: Otting
mesh_terms: D003035:Cobalt / Q000737:chemistry; D029968:Escherichia coli Proteins / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D009113:Muramidase / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular; D010848:Picolinic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012097:Repressor Proteins / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: C550334:3-mercapto-2,6-pyridinecarboxylic acid; C490177:ArgR protein, E coli; D029968:Escherichia coli Proteins; D028581:Lanthanoid Series Elements; D010848:Picolinic Acids; D012097:Repressor Proteins; D013438:Sulfhydryl Compounds; D003035:Cobalt; D009113:Muramidase