title: 7Li nuclear-magnetic-resonance study of lithium binding to myo-inositolmonophosphatase.
abstract: The interaction of Li+ with myo-inositol monophosphatase was studied by 7Li-NMR spectroscopy. Li+ binding to the enzyme induces a downfield shift and broadening of the 7Li-NMR signal. Changes of the chemical shift were used to follow the titration of the enzyme with lithium and to determine a dissociation constant, Kd = (1.0 +/- 0.1) mM. Only one major binding site/enzyme subunit was inferred. The complex forms independently of the presence of inorganic phosphate. Metals from the group IIa of the periodic table compete with Li+ binding with the affinity increasing in the order Mg2+ < Ca2+ < Be2+. In contrast to lithium, their binding is enhanced by phosphate.
authors.affiliation: Marion Merrell Research Institute, Strasbourg, France.
authors.forename: V
authors.initials: V
authors.lastname: Saudek
authors.forename: P
authors.initials: P
authors.lastname: Vincendon
authors.forename: Q T
authors.initials: QT
authors.lastname: Do
authors.forename: R A
authors.initials: RA
authors.lastname: Atkinson
authors.forename: V
authors.initials: V
authors.lastname: Sklenar
authors.forename: P D
authors.initials: PD
authors.lastname: Pelton
authors.forename: F
authors.initials: F
authors.lastname: Piriou
authors.forename: A J
authors.initials: AJ
authors.lastname: Ganzhorn
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002413:Cations, Divalent / Q000378:metabolism; D003001:Cloning, Molecular; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D007672:Kidney Cortex / Q000201:enzymology; D007700:Kinetics; D008094:Lithium / Q000378:metabolism*; D046911:Macromolecular Substances; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
chemical_list: D002413:Cations, Divalent; D007527:Isoenzymes; D046911:Macromolecular Substances; D011994:Recombinant Proteins; D008094:Lithium; D010744:Phosphoric Monoester Hydrolases; C021822:myo-inositol-1 (or 4)-monophosphatase