[NMR paper] X-ray absorption and NMR spectroscopic studies of CopZ, a copper chaperone in Bacillu

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X-ray absorption and NMR spectroscopic studies of CopZ, a copper chaperone in Bacillus subtilis: the coordination properties of the copper ion.

Related Articles X-ray absorption and NMR spectroscopic studies of CopZ, a copper chaperone in Bacillus subtilis: the coordination properties of the copper ion.

Biochemistry. 2003 Mar 4;42(8):2467-74

Authors: Banci L, Bertini I, Del Conte R, Mangani S, Meyer-Klaucke W

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. (1)H and (15)N 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.

PMID: 12600214 [PubMed - indexed for MEDLINE]



Source: PubMed