Tools
ToolsZhou, Liang, Singleton, Chloe and Le Brun, Nick E. (2008) High Cu(I) and low proton affinities of the CXXC motif of Bacillus subtilis CopZ. Biochemical Journal, 413 (3). 459–465. ISSN 0264-6021
Full text not available from this repository.Abstract
CopZ, an Atx1-like copper chaperone from the bacterium Bacillus subtilis, functions as part of a complex cellular machinery for Cu(I) trafficking and detoxification, in which it interacts specifically with the transmembrane Cu(I)-transporter CopA. Here we demonstrate that the cysteine residues of the MXCXXC Cu(I)-binding motif of CopZ have low proton affinities, with both exhibiting pKa values of 6 or below. Chelator competition experiments demonstrated that the protein binds Cu(I) with extremely high affinity, with a small but significant pH-dependence over the range pH 6.5–8.0. From these data, a pH-corrected formation constant, ß2=~6×1022 M-2, was determined. Rapid exchange of Cu(I) between CopZ and the Cu(I)-chelator BCS (bathocuproine disulfonate) indicated that the mechanism of exchange does not involve simple dissociation of Cu(I) from CopZ (or BCS), but instead proceeds via the formation of a transient Cu(I)-mediated protein–chelator complex. Such a mechanism has similarities to the Cu(I)-exchange pathway that occurs between components of copper-trafficking pathways.
| Item Type: | Article |
|---|---|
| Faculty \ School: | Faculty of Science > School of Chemistry (former - to 2024) |
| UEA Research Groups: | Faculty of Science > Research Groups > Biophysical Chemistry (former - to 2017) Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences Faculty of Science > Research Centres > Centre for Molecular and Structural Biochemistry Faculty of Science > Research Groups > Chemistry of Life Processes |
| Depositing User: | Rachel Smith |
| Date Deposited: | 07 Apr 2011 14:16 |
| Last Modified: | 29 Jan 2025 11:04 |
| URI: | https://ueaeprints.uea.ac.uk/id/eprint/28488 |
| DOI: |
Actions (login required)
 |
View Item |