Emerging Strategies in Metalloproteomics

The impact of changing metal ion concentrations on infection with a pathogenic microorganism has been established in several cases. To understand the molecular basis of the interplay between metals in the host and the pathogen in infectious diseases, metalloproteomics may prove to be a very powerful approach. Metalloproteomics is the comprehensive analysis of all metal-binding and metal-containing proteins in a biological sample. Strategies in metalloproteomics can be divided into experimental and computer-based approaches. Samples that have been analyzed using metalloproteomics strategies are cell lysates, subcellular fractions, and recombinantly expressed proteins from structural genomics platforms. Samples can be enriched in metal-binding protein by using immobilized metal ion affinity chromatography ( IMAC). Subsequently, metalloproteins have been separated using either 2D electrophoresis or 2D liquid chromatography ( LC). Resolved proteins have been further analyzed for metals and protein content. Inductively coupled plasma mass spectrometry ( ICP-MS), X-ray absorbance or fluorescence and autoradiography of radioactive metal isotopes have been used to determine the metal content, and different soft ionization mass spectrometry techniques and SDS-PAGE have been used to determine or quantify protein content. Computer-based strategies have been developed to predict metalloproteomes from genomes based on information from literature resources and different genomic and protein structural databases. Many of the methods presented here are comprehensive in nature. The interplay of computer-based and experimental strategies in metalloproteomics will significantly advance the field in the near future.