Why is sodium hydroxide affect catalase reaction with hydrogen peroxide?

[skipwner]

While doing a simple experiment with different pH levels and catalase, I came across something really peculiar. For some reason when I add sodium hydroxide to hydrogen peroxide and add my catalase (chicken liver) I find that the pH level of 10 is releasing more oxygen than the pH level of seven. I originally thought that when anything over 7.5 would denature the catalase, but according to my data that didn't happen. Is sodium hydroxide some sort of inhibitor for catalase or did I make a mistake? O we used an o2 sensor that was calibrated perfectly before the experiment so there was no error in that. Anybody have any idea?

[skipwner]

Can anyone please help me? Im still stumped.

[Jens]

pH 7.4 is typical pH within a cell. I doubt that any human enzyme which is supposed to act within a cell will be denatured at pH 7.5 (since this means it will partially denature already at usual pH level). Where did this information come from?

 

wikipedia is stating that catalase pH Optimum varies by species from pH 4 to 11. (follow the reference -- no pH optimum given for gallus gallus -- chicken)

 

If you do not have any different data, I would simply assume that the pH optimum of your enzyme is closer to 10 than to 7.

Jens