Difference between revisions of "Part:BBa K1456006"

Revision as of 15:33, 23 October 2014

Aprotinin: Oxygen Radical Inhibitor

• Also known as pancreatic trypsin inhibitor or serine protease inhibitor, aprotinin is a potent protease inhibitor. According to our researches, aprotinin prevents the formation of xanthine oxidase (XO) from xanthine dehydrogenase (XDH). XO catalyzes the end step of xanthine degradation pathway resulting with ROS formation. In fact, about 80% of ROS during oxidative stress is produced by this enzyme. Furthermore, harmful free radicals such as peroxynitrite can be built up owing to the products of XO. Such free radicals have been found to react with DNA, proteins, and cells, causing cellular damage or even toxicity.
• Another reaction catalyzed by xanthine oxidase is the decomposition of S-Nitrosothiols (RSNO), a reactive nitrogen species, to nitric oxide (NO), which reacts with a superoxide anion to form peroxynitrite under aerobic conditions, additionally.This enzyme catalyzes the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid. Both XO and XDH enzymes play an important role in the catabolism of purines.
• Inhibition of xanthine oxidase has been proposed as a mechanism for improving cardiovascular health. (Dawson et al. 2006) A study found that patients with chronic obstructive pulmonary disease (COPD) had a decrease in oxidative stress, including glutathione oxidation and lipid peroxidation, when xanthine oxidase was inhibited using allopurinol. (Heunks et al. 1999) Oxidative stress can be caused by hydroxyl free radicals and hydrogen peroxide, both of which are byproducts of XO activity. (Higgins et al. 2009)