An Iron-Messenger System - A Hypothesis

Iron in the free ionic state is very reactive as it generates and reacts with free radicals of the type HO, LO, LOO', O^?₂ and C. These are highly reactive species and participate in reactions that are mostly deleterious to cell components, including DNA, proteins and lipids. In association with a complexing agent such as bleomycin, Fe²⁺ degrades DNA into soluble nucleotides'. In the presence of oxygen and a reducing agent, DTT, Fe²⁺ inacativates enzymes by peptide bond cleavage². Chelated to ADP, Fe²⁺ promotes peroxidation of polyunsaturated fatty acids and breakdown of membranes³. These do not occur in normal cells as they are kept under check by antioxidant devices, and more importantly by keeping free iron concentration low.