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Updated: Jun 20, 2026
11:38
Quantifying the Binding Interactions Between Cu(II) and Peptide Residues in the Presence and Absence of Chromophores
Published on: April 5, 2022
Copper binding to beta-2-microglobulin and its pre-amyloid oligomers
Rapole Srikanth1, Vanessa Leah Mendoza, Juma D Bridgewater
1Department of Chemistry, University of Massachusetts, Amherst, Massachusetts 01003, USA.
Biochemistry
|September 17, 2009
Summary
Copper (Cu(II)) binding to beta-2-microglobulin (beta2m) drives amyloid formation in dialysis patients. This study reveals how Cu(II) binding sites change from monomer to oligomers, facilitating self-assembly and amyloidogenesis.
Area of Science:
- Biochemistry
- Structural Biology
- Materials Science
Background:
- Beta-2-microglobulin (beta2m) forms amyloid fibrils in patients with kidney failure undergoing long-term dialysis.
- Copper (Cu(II)) binding induces beta2m oligomerization, preceding amyloid formation.
- The evolution of the Cu(II) binding site during beta2m self-assembly is not fully understood.
Purpose of the Study:
- To investigate the dynamic changes in the Cu(II) binding site of beta2m during oligomerization.
- To elucidate the structural mechanisms by which Cu(II) binding facilitates beta2m self-assembly into amyloid fibrils.
Main Methods:
- Utilized three mass spectrometry (MS)-based methods to analyze Cu(II)-beta2m interactions.
- Characterized the Cu(II) coordination environment in monomeric, dimeric, and tetrameric beta2m species.
Main Results:
- Identified the Cu(II) binding site in monomeric beta2m involving the N-terminal amine, Gln2, His31, and Asp59.
- Observed that in dimers and tetramers, Asp59 detaches from Cu(II), weakening the binding site and facilitating Cu(II) release.
- Found that Cu(II) binding induces repositioning of Asp59 and Arg3, promoting the formation of stabilizing salt bridges crucial for oligomerization.
Conclusions:
- Cu(II) binding to beta2m involves a dynamic site that evolves during oligomerization, promoting amyloid formation.
- The structural rearrangements triggered by Cu(II) binding, including residue repositioning and salt bridge formation, are key to beta2m self-assembly.
- Tetramers represent an early Cu(II)-free oligomeric species, consistent with previous findings.
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