Metal-binding properties of amino acids and peptides

2 Metal-binding properties of amino acids and peptides 

Special mention must be made of the thiol group in the side-chain of cysteine, which has a high affinity for Ag+ and Hg2+ ions. It will be seen later that Hg2+ ions are used to remove Acm protecting groups from cysteine side-chains (Section 7.5.2). The ease with which this type of reaction occurs is a consequence of this high affinity of Hg2+ ions for divalent sulphur. 

3 An introduction to the routine aspects and the specialised aspects of the spectra of amino acids and peptides 

Interpretation of spectrometric features of amino acids and peptides and their derivatives has its routine aspects, but the spectra of these compounds also incorporate unique detail that provides specific information about the behaviour of amino acids and peptides in solution. These methods reveal the ways in which groupings within a peptide in solution relate to each other and these details are of major importance in determining the physical and physiological properties of amino acids and peptides. Conformational studies (Chapter 2) and structure determinations for peptides have been the priority targets for investigations by physicochemical methods. 

The routine category, the use of spectrometry in support of synthetic and investigative studies (verification of the course of a synthesis or of reactions of amino acids and peptides, for example) is a topic that has been covered by numerous textbooks. A thorough coverage of this topic is therefore not provided here and the reader is assumed to know the background relating to the uses of the techniques (and the reader is also assumed to be prepared to consult standard texts for any more detailed explanation that may be needed). 

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