Abstract
The metal-binding affinities and three-dimensional structures of three synthetic 18-residue peptides with sequences derived from that of the highly conserved metal-binding motif MXCXXC found in many heavy metal-binding proteins were determined. A change in register of the cysteines and alanines of the sequence from the periplasmic mercury-binding protein, MerP, i.e., CAAC, CACA, and CCAA, affects the specificity of metal binding, in particular, the peptide with vicinal cysteines binds only mercury. The three-dimensional structures of the mercury-bound forms of the three peptides determined in solution by NMR spectroscopy peptides differ considerably, even though they are all linear bicoordinate complexes. The three-dimensional structure of the peptide with CAAC bound to Cd(II) demonstrates that the metal-binding loop is malleable enough to accommodate modes of coordination other than linear bicoordinate.
Original language | English (US) |
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Pages (from-to) | 189-197 |
Number of pages | 9 |
Journal | Biopolymers |
Volume | 64 |
Issue number | 4 |
DOIs | |
State | Published - Aug 5 2002 |
Keywords
- Cadmium
- Mercury
- Mercury-binding protein
- NMR spectroscopy
- Peptides