Journal article

Evaluation of Cu(I) binding to the E2 domain of the amyloid precursor protein - a lesson in quantification of metal binding to proteins via ligand competition

Tessa R Young, Anthony G Wedd, Zhiguang Xiao



The extracellular domain E2 of the amyloid precursor protein (APP) features a His-rich metal-binding site (denoted as the M1 site). In conjunction with surrounding basic residues, the site participates in interactions with components of the extracellular matrix including heparins, a class of negatively charged polysaccharide molecules of varying length. This work studied the chemistry of Cu(i) binding to APP E2 with the probe ligands Bcs, Bca, Fz and Fs. APP E2 forms a stable Cu(i)-mediated ternary complex with each of these anionic ligands. The complex with Bca was selected for isolation and characterization and was demonstrated, by native ESI-MS analysis, to have the stoichiometry E2 : Cu(..

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Awarded by Australian Research Council

Funding Acknowledgements

This work was supported by funds from the Australian Research Council Grant DP130100728. Additional financial support for TRY was generously provided by the Norma Hilda Schuster (nee Swift) Scholarship Fund and the Albert Shimmins Fund. We thank Associate Professor Tara Pukala (University of Adelaide) for assistance with native ESI-MS experiments. Additional ESI-MS analysis was conducted at the Bio21 Mass Spectrometry and Proteomics Facility. We thank Professor Roberto Cappai (University of Melbourne) for kindly donating the Pichia pastoris strain expressing APP D2.