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A Study of the Complexation of Mercury(II) with Dicysteinyl Tetrapeptides by Electrospray Ionization Mass Spectrometry
Published on: January 8, 2016
Molecular mimicry in mercury toxicology
Ruth E Hoffmeyer1, Satya P Singh, Christian J Doonan
1Department of Geological Sciences, University of Saskatchewan, Saskatoon, Canada.
Chemical Research in Toxicology
|June 20, 2006
Summary
Molecular mimicry, where toxic metals like methylmercury enter tissues, was investigated. Structural similarities are insufficient for mimicry; instead, a less specific mimicry involving the amino acid region is proposed.
Area of Science:
- Biochemistry
- Toxicology
- Computational Chemistry
Background:
- Molecular mimicry explains how molecules are mistaken by biological processes due to structural similarities.
- It is hypothesized to be crucial for toxic metal uptake into tissues.
- Methylmercury-cysteine transport, mimicking methionine, is a proposed example.
Purpose of the Study:
- To investigate the solution structure of methylmercury-cysteine complexes.
- To elucidate the structural basis of molecular mimicry in toxic metal uptake.
- To compare the structures of methionine and cystine with their corresponding mercury complexes.
Main Methods:
- Mass spectrometry
- Mercury L(III)-edge X-ray absorption spectroscopy
- Computational chemistry
Main Results:
- Determined the solution structure of methylmercury-cysteine complexes.
- Compared structural similarities between methionine and methylmercury-cysteine.
- Compared structural similarities between cystine and mercury(II) bis-L-cysteineate.
Conclusions:
- Structural similarities between metal compounds and natural products are insufficient to support molecular mimicry.
- A less-specific mimicry mechanism, based on the L(alpha) region of amino acids, is proposed for toxic metal uptake.
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