New Tools & Techniques for the Metallomics Revolution

The metallome has been defined as the complete complement of metals and metal moieties in a biological cell, tissue, or system. This definition is akin to that of the genome (genes), proteome (proteins), and metabolome (metabolites). Metallomics accordingly is the study of metals and metal species, and their interactions, transformations, and functions in biological systems. While traditional bioinorganic chemistry has focused on the role and interactions of a single (or few) metals in a protein or enzyme system, metallomics purports to study global, multi-element interactions and relationships. The metallomics challenges for analytical chemistry and biochemical characterization are significant. This paper will discuss these challenges and the emergent techniques and tools that are being developed to address them. Mass spectrometry will play an important and pivotal role. Two approaches are currently being developed in the authors' laboratories. At Pacific Northwest National Laboratory, an extremely high-resolution approach using Fourier Transform Ion Cyclotron Resonance mass spectrometry (FT-ICRMS) is under development. At Indiana University, a rapid, dual-reflectron Time-of-Flight mass spectrometry (TOFMS) technique is being developed. Both approaches rely on dual inductively coupled plasma (ICP) and electrospray ionization (ESI) sources for elemental and biomolecular ion generation. The initial development of these techniques, and their potential application to systems biology and environmental characterization, will be discussed.