Biological iron trafficking: The beauty of redox potentials

INOR 65

S. Dhungana, dhungana@chem.duke.edu, Chemistry Department, Duke University, Box 90346, Durham, NC 27708-0346 and Alvin L. Crumbliss, alc@chem.duke.edu, Department of Chemistry, Duke University, Durham, NC 27708.
Iron acquisition, storage and transport are essential processes involved in the biochemistry of iron. Coordination chemistry, along with acid-base and redox chemistry, are important aspects that control the mobility and storage of iron in the environment and in living systems. The time and site-specific delivery of this essential nutrient is a fundamental challenge in biological iron trafficking and it can potentially be modulated by controlling the reduction potential of biological Fe(III)-complexes. Here we explore a redox-driven hypothesis of iron release from stable Fe(III) transport agents critical to mammalian and microbial iron transport. The role of the Fe(III)/Fe(II) redox couple as a thermodynamic, kinetic and protonation switch for iron release and the factors that control this redox couple will be illustrated with specific examples from mammalian and microbial systems using low and high molecular weight carriers.