XAS studies have been performed, under various experimental conditions, on a copper(I)transporting protein, CopZ, of Bacillus subtilis. The copper(I) ion, reduced with dithiothreitol, is three-coordinate with three sulfur donor atoms, two of which presumably provided by the protein and one by dithiothreitol. If a molar excess of acetate (15 mM; 5:1 respect to CopZ) or citrate (6 mM; 2:1 respect to CopZ) is present in solution, the EXAFS spectra suggest the presence of a dimeric form involving a close contact between Cu(I) ions from two molecules, where Cu is still three-coordinate. H-1 and N-15 NMR data provide further structural details. If copper reduction is accomplished with ascorbate, the data indicate that one oxygen of ascorbate enters in the first-coordination sphere of copper, together with two sulfur atoms, in a dimeric form of the protein. These results are instructive and have been discussed with respect to the molecular basis of copper trafficking.
Banci, L., Bertini, I., Conte, R.D., Mangani, S., Meyer Klaucke, W. (2003). X-ray absorption and NMR spectroscopic studies of CopZ, a copper chaperone in Bacillus subtilis: The coordination properties of the copper ion. BIOCHEMISTRY, 42(8), 2467-2474 [10.1021/bi0205810].
X-ray absorption and NMR spectroscopic studies of CopZ, a copper chaperone in Bacillus subtilis: The coordination properties of the copper ion
Bertini, I.;Mangani, Stefano;
2003-01-01
Abstract
XAS studies have been performed, under various experimental conditions, on a copper(I)transporting protein, CopZ, of Bacillus subtilis. The copper(I) ion, reduced with dithiothreitol, is three-coordinate with three sulfur donor atoms, two of which presumably provided by the protein and one by dithiothreitol. If a molar excess of acetate (15 mM; 5:1 respect to CopZ) or citrate (6 mM; 2:1 respect to CopZ) is present in solution, the EXAFS spectra suggest the presence of a dimeric form involving a close contact between Cu(I) ions from two molecules, where Cu is still three-coordinate. H-1 and N-15 NMR data provide further structural details. If copper reduction is accomplished with ascorbate, the data indicate that one oxygen of ascorbate enters in the first-coordination sphere of copper, together with two sulfur atoms, in a dimeric form of the protein. These results are instructive and have been discussed with respect to the molecular basis of copper trafficking.File | Dimensione | Formato | |
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https://hdl.handle.net/11365/32169
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