Analytical characterization of bioactive metal species in the cellular domain (metallomics) to simplify environmental and biological proteomics

Abstract

The speciation approach for the characterization of low-mass metal species including sample treatment and storage is at present a well-established topic based on chromatography-atomic detector coupling. More recently, new endogenous and exogenous metal species from biological systems are attracting considerable interest. Bioactive molecules such as proteins, DNA restriction fragments, phytochelatins, metallothioneins and others are target species of a new generation of analytical tools (bioanalysis) which substitute the traditional atomic detectors based on the use of photons (AAS, FPD, ICP-AES, AFS) by mass detectors (MS and ICP-MS) for ion characterization. Several cases related to biological molecules involving proteins and multiprotein systems, in which frequently metals (metallomics) participate, are described, and a generic metallomic analytical approach is proposed for the identification and quantification of metalloproteins, and other metal molecules present in living systems. In this work, a multiplexed analytical approach (MAA) is described on the basis of three experimental components: (1) a separation technique—selectivity component; (2) a highly sensitive elemental detector—sensitivity component; and (3) a molecule-specific detector, generally based on mass spectrometry—structural component. This approach brings together both elemental and molecular detectors to simplify the identification of metal-tagged biomolecules in environmental, food, and health studies.

Keywords:

• Metallomics
• Metalloproteins
• Proteins
• Speciation
• Mass spectrometry

Acknowledgements

The authors would like to thank ‘Ministerio de Ciencia y Tenología (MCyT)’ for the Grant REN2002-04366-C02-02. T. Garcia-Barrera thanks Universidad de Huelva for a scholarship. F. Lorenzo thanks Junta de Andalucia for a pre-doctoral grant.