Malondialdehyde generation and its consequences

Peroxyl radicals 4.2 can also evolve to cyclic endoperoxides by attack onto a neighboring C=C double bond in the same chain, as shown in Figure 4.6 for the case of a molecule of arachidonic acid, in a process resembling the one catalyzed by cyclooxygenase. Peroxyl radicals 4.2 may lead to lipid peroxidation, as previously mentioned (Fig. 4.5). Alternatively, they can cyclize to radical 4.4, which then undergoes a new cyclization, coupled with the addition a second oxygen molecule and subsequent reduction of the hydroperoxyl radical thus generated, to give 4.5. Together with other products, these intermediates generate malondial-dehyde (MDA) through a retro Diels-Alder mechanism.

MDA can link covalently to amino groups in proteins, especially at Lys residues, resulting in intra- and intermolecular protein cross-links (Fig. 4.7A).

FIGURE 4.5 Phospholipid peroxidation.

Arachidonic acid esterified in membrane

Other products -

Arachidonic acid esterified in membrane

Other products -

CO2R

CO2R

co2r

10 Ways To Fight Off Cancer

10 Ways To Fight Off Cancer

Learning About 10 Ways Fight Off Cancer Can Have Amazing Benefits For Your Life The Best Tips On How To Keep This Killer At Bay Discovering that you or a loved one has cancer can be utterly terrifying. All the same, once you comprehend the causes of cancer and learn how to reverse those causes, you or your loved one may have more than a fighting chance of beating out cancer.

Get My Free Ebook


Post a comment