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Updated: Jun 17, 2026

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Cu(I) binding properties of a designed metalloprotein
Fei Xie1, Duncan E K Sutherland, Martin J Stillman
1Department of Chemistry and Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43403, USA.
This study investigates copper(I) binding to a designed peptide, C16C19-GGY. It reveals cooperative formation of a tetranuclear copper cluster and a secondary lower-affinity binding site, impacting peptide emission.
Area of Science:
- Biochemistry
- Bioinorganic Chemistry
- Peptide Design
Background:
- Designed peptide C16C19-GGY aims for alpha-helical coiled-coil formation.
- Incorporates a Cys-X-X-Cys motif for metal binding on its hydrophobic face.
Purpose of the Study:
- To characterize the copper(I) binding properties of the designed peptide C16C19-GGY.
- To elucidate the structural and functional consequences of copper(I) coordination.
Main Methods:
- Absorption and emission spectroscopy
- Electrospray ionization mass spectrometry (ESI-MS)
- Circular dichroism (CD) spectroscopy
- Spectroscopic titrations
Main Results:
- A 1:1 copper(I)-peptide complex forms initially, existing as a tetramer with a tetranuclear copper cluster.
- ESI-MS and UV data confirm cooperative formation of the tetranuclear copper cluster.
- A second, lower affinity copper(I) binding site is occupied upon further addition, quenching 600nm emission without altering peptide conformation.
- Tris(2-carboxyethyl)phosphine (TCEP) competitively inhibits binding to the low affinity site but not the clusters.
Conclusions:
- The peptide C16C19-GGY facilitates cooperative formation of a tetranuclear copper(I) cluster.
- A secondary copper(I) binding site influences peptide emission properties.
- The peptide's conformational stability is maintained across different copper(I) binding states.
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