Biophysical probes of iron metabolism in cells and organelles.

In living systems, iron is found in many different structures, including Fe/S clusters, hemes and nonheme centers, and magnetically interacting aggregates. Understanding Fe metabolism and trafficking will require biophysical spectroscopic tools that can evaluate the types of Fe centers within entire cells and isolated organelles. Mössbauer spectroscopy will play an important role in such analyses, as it has perhaps the best combination of resolution, sensitivity, coverage, and quantifying abilities. Other spectroscopic techniques, with particular strengths, will be used in combination with Mössbauer, and results will be integrated to assess the 'ironome' of such complex samples. This integrative biophysical approach is illustrated by a discussion of iron trafficking in yeast cells.