Iron Role in the Oxidative Metabolism of Animal and Plant Cells. Effect of Iron Overload.

NATACHA E. PILONI Y SUSANA PUNTARULO

Metals in Biology Systems.

Research Signpost, Transworld Research Network

Lugar: Kerala; Año: 2010; p. 29 - 50

            Fe is a micronutrient essential for life. The amount of Fe within both, animal and plant cells, is carefully regulated to provide an adequate level and to prevent its accumulation and toxicity. Fe excess generates oxidative stress, understood as an increase in the steady state concentration of oxygen radical intermediates. The one-electron interconversion between Fe(II) and Fe(III), which makes Fe the key factor for biological redox processes, is also the ability that becomes Fe toxic. After Fe incorporation and internalization into cells, the metal is removed from transferrin (Tf) and transported across the endosomal membrane to the cytosol. Once in the cytosol, Fe is bound rapidly to a variety of compounds to avoid its precipitation due to its very low solubility at pH 7 (KspFe(III) =10-17 M). A major fraction of this Fe would be very fast inserted in ferritin (Ft), the main protein designed to storage Fe in a safe way. However, Fe must be available to the various cell compartments to fulfill its functions, so Fe must be efficiently released from storage proteins. The released Fe is bound to low-molecular-weight molecules giving a steady state concentration of transient Fe within the cell, known as labile Fe pool (LIP). The main aspects of animal and plant cellular metabolism of Fe, with special emphasis in the role of Fe on the oxidative damage and the effects of Fe overload, are briefly reviewed here.