Analytical methods are being used to study metal-protein interactions, providing a starting point for protein mapping.

A team led by Gunda Koellensperger at the University of Natural Resources and Applied Life Sciences in Vienna, Austria, has combined separation and analytical techniques to study proteins containing copper. Metal-containing proteins make up a large proportion of any living organism's proteome (the proteins produced from the genome), and metallomics is the study of these proteins. Koellensperger explained that the development of methods to examine metals in proteins is 'needed to understand the role of the metal in complex biochemical processes.' 

Koellensperger has shown that investigating metal-protein interactions requires several different but complementary methods, involving various separation and mass spectrometry techniques. Combined, these provide accurate details of protein structure, including information about metal-binding. Also, isotopically-enriched amino acids or protein-altering mutations can be detected. This gives a complete protein picture which already has applications, for example in the quality control of artificially produced metalloproteins. 

Heidi Goenaga-Infante, from the Laboratory of the Government Chemist in the UK, whose research interests include metal detection in biological samples, is impressed. She describes the work as 'a very good example' demonstrating the potential of combining elemental and molecular mass spectrometry to obtain important information about proteins.

Koellensperger says the study is an important starting point towards comprehensive metalloprotein mapping in biological samples, but adds that further progress depends on new separation methods being developed.

Laura Howes