1. The exchange of histidine C-2 protons in superoxide dismutases. A novel method for assigning histidine-metal ligands in proteins
- Author
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J.V. Bannister, Anthony E. G. Cass, V Hasemann, Hugh Allen Oliver Hill, J T Johansen, and William H. Bannister
- Subjects
Magnetic Resonance Spectroscopy ,Chemical Phenomena ,Stereochemistry ,chemistry.chemical_element ,Saccharomyces cerevisiae ,Zinc ,Ligands ,Biochemistry ,Superoxide dismutase ,Metal ,Protein structure ,Methods ,Metalloprotein ,Animals ,Histidine ,Molecular Biology ,chemistry.chemical_classification ,biology ,Superoxide Dismutase ,Ligand ,Cell Biology ,Deuterium ,Chemistry ,Enzyme ,chemistry ,visual_art ,biology.protein ,visual_art.visual_art_medium ,Cattle ,Protons ,Copper ,Research Article - Abstract
The rates of exchange of the C-2 protons of histidine residues in copper-zinc superoxide dismutase are substantially decreased by metal ion binding. This observation was used to distinguish between ligand and non ligand histidine residues in bovine and yeast copper-zinc superoxide dismutases; the effect was shown to depend only on metal ion co-ordination and not as a consequence of concomitant changes in protein structure. Selective deuteration of the zinc-only proteins at pH (uncorrected pH-meter reading) 8.2 and 50 degrees C resulted in the distinction between copper and zinc ligand resonances in the 1H n.m.r. spectrum of the enzymes. This method is proposed as a generally applicable technique for identifying histidine residues as ligands in metalloproteins.
- Published
- 1979
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