In situ spectroscopies unravel metal ion speciation within biological tissue

Abstract

I will describe two scientific problems that drive the laboratory’s work. The first and more general question is how metal ions reach their final destinations as cofactors of proteins in different cell types and subcellular compartments. In other words, how cells ensure the binding of specific metals – required for enzyme activity – into protein ‘pockets’ that can in principle accommodate more than one metal ion type. The second problem focuses on the specific case of zinc ions and asks how animals detect whether they require more of less of this ion to regulate accordingly its absorption, storage or release, and excretion mechanisms.

Besides sharing the direction of our research program, the presentation will describe the methodologies that have enabled us to meaningfully apply XAS, NMR, EPR, and fluorescence-based spectroscopies, typically performed on pure chemical systems, to extract valuable information directly from tissue samples. The importance of determining in this way metal ion speciation within the biological setting will be discussed.

Reference: Tryptophan Regulates Drosophila zinc stores. Proceedings of the National Academy of Sciences (2022) https://doi.org/10.1073/pnas.2117807119

Speakers Short CV

Fanis Missirlis studied Biology at the University of Patras (Greece). His PhD demonstrated the biological and chemical specificity of reactive oxygen species and relevance of cellular sites of their production in relation to observed effects, working with Herbert Jäckle at the Max-Planck Institute (Göttingen, Germany) and John P. Phillips at the University of Guelph (Canada). As a postdoctoral fellow in Tracey Rouault’s laboratory at the National Institutes of Health (USA), he introduced Drosophila molecular genetics in iron metabolism research. While serving as a Lecturer in Cell Biology at Queen Mary University of London (United Kingdom), he became interested in the problem of how biological systems discriminate iron from other metal ions and differentially handle their chemistries. Presently, he directs the BioMetallomics Laboratory at the Center for Research and Advanced Studies of the National Polytechnic Institute (Mexico). https://fanis.fisio.cinvestav.mx