hi i working on polyphenoloxidase enzyme by using catechol as a substrate but the activity was very week or disappear, and when i added H2O2 with catechol the activity become high . can anyone explain that? thanks
This oxidation was under aerobic or anaerobic conditions ?
Either way maybe the copper in the enzyme catalysed the decomposition of H2O2 to water and di-oxygen, then the oxygen is consumed in the oxidation reaction of catechol which could explain the increase in the rate.
The hydrogen peroxide is a very strong oxidizing agent which can convert the catechol to its oxidased from.... that might be the reason for the behavior you obtained.. The other thing that you need to think about is that the presence of the hydrogen peroxide might block a hidden factor that can affect the enzyme activity