Analysis of Iron in Ferritin, the Iron-Storage Protein: A General Chemistry Experiment

The chemical properties of the iron-storage protein ferritin will be examined in this experiment by quantitating the average amount of iron in a ferritin sample, and observing the kinetics of iron release from the protein core under reducing conditions. Students learn and apply the principles of absorption spectroscopy, redox reactions, and metal chelation to study ferritin. The presentation of the basic concepts of protein and molecular structure is greatly enhanced through the use of a computer-based graphical tutorial which is available on the World Wide Web on the on the Washington University Department of Chemistry homepage. The computer-based tutorial serves as an introduction to three-dimensional structure and molecular structure-function relationships. The experiment is derived from a standard general-chemistry experiment in which the concentration of an iron unknown is determined spectroscopically using a chromophoric indicator. However, application of this technique to ferritin, which stores iron as an iron-oxide mineral core, helps to develop links between general chemistry and biology, and to use biological importance as a driving force for studying chemistry.