Inhibition of horseradish peroxidase activity by thiol type inhibitors

✍ Scribed by R. Sariri; R.H. Sajedi; V. Jafarian

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 94 KB
• Volume: 123
• Category: Article
• ISSN: 0167-7322
• DOI: 10.1016/j.molliq.2005.05.004

✦ Synopsis

The inhibition by cysteine and glutathione of 4-amino antipyrine oxidation by horseradish peroxidase was compared. The kinetics of the peroxidase inhibition by glutathione was investigated and compared to l-cysteine inhibition. IC 50 for l-cysteine and glutathione was determined and used for the subsequent kinetics studies. The biological activity of the enzyme was measured in the presence of each inhibitor using 4-amino antipyrine as substrate. It was found that reduced glutathione was a more potent inhibitor on peroxidase activity than lcysteine. Kinetic studies showed that inhibition was non-competitive and mixed type in both cases. The values of K m and V max in the presence of each inhibitor were also calculated.