Fenton-type reactions in lipids

As stressed throughout this book, lipid oxidation is one of the more important biological radical processes. Being a chain reaction, only low concentrations of initiators are required, and it has been argued that an important initiator may be a Fenton type reaction. 

The main problem with this concept is one of solubility. The site of attack is the double-bonded part of the lipids, embedded in the centre of the membrane. Not only are Fe(II) complexes unlikely to be present, but also H202 is unlikely to be present in the inner region of the phospholipid double layer. Thus, the probability of there being sufficient of each to initiate autoxidation seems to us to be very low indeed. Nevertheless, catalysis by metal ions does occur. Possibly, membrane proteins are involved in some way. 

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