Christoph Fahrni (Chemistry, Georgia Institute of Technology, Atlanta, USA)
Abstract: Approximately 40% of the proteins in our body require one or multiple metal ions for their proper function. These metalloproteins serve a wide range of biological roles, for example they are utilized for catalyzing metabolic processes, regulating genes, or transducing biochemical signals. While the elucidation of the function of metalloproteins has been a longstanding theme in bioinorganic research, the question of how cells acquire, store, and regulate metal cations only more recently moved into the spotlight. This trend has been particularly stimulated by the discovery that impaired metal transport and regulation are the cause of numerous number severe diseases, including hemochromatosis, Menkes syndrome, and Alzheimer's disease. Given the small size of cellular structures and the low abundance of many of the relevant metal ions, the investigation of their dynamics and distribution, ideally within the native physiological environment of tissues, cells, or organelles, poses significant analytical challenges. Furthermore, living biological systems inherently operate in an non-equilibrated state, and for this reason, many traditional biochemical methods only offer limited insights into the inner workings of trace metal regulation and trafficking. To truly understand the dynamics of these processes, state of the art experimental techniques are required that are capable of tracking metal ion distributions within individual cells and capturing stochastic events at the single molecule level, followed by processing of the data with suitable mathematical models. This presentation is intended to offer a brief overview of recent developments in the field of in situ imaging of trace metals and to provide a guide to some of the most pertinent challenges in this line of research.