What does it mean when the % residual activity of an enzyme after inhibition by an inhibitor compound is more than 100%, let's say 120 or 180%?
If the activity of an enzyme in the presence of a compound is higher than in its absence, then the % residual activity would be greater than 100%. This could be a real stimulatory effect, or it could be an artifact due to interference by the compound with the measurement, as suggested by Amog P Urs.
That is a silly way to ask a question. The question should be "under these specific conditions, what is the % residual activity of an enzymatic reaction in the presence of xx amount of inhibitor?".
% Residual activity will be less than 100% in presence of an inhibitor. It will never become more than 100% even in the absence of an inhibitor.
May be your inhibitor is absorbing at that OD, you keep inhibitor alone control and subtract the inhibitor alone OD with enzyme activity OD. Then you will get correct residual activity after inhibition.
If the activity of an enzyme in the presence of a compound is higher than in its absence, then the % residual activity would be greater than 100%. This could be a real stimulatory effect, or it could be an artifact due to interference by the compound with the measurement, as suggested by Amog P Urs.
Which is the enzyme & the corresponding inhibitor that is being referred to in this case?
what is the meaning of percentage residual activity in the presence of enzyme inhibitors.
You have 2 measurements of enzyme activity: an uninhibited control (MAX) and a partially inhibited sample (X). The % residual activity is 100% x (X/MAX). For example, suppose the activity measurement in the uninhibited control is 1.75 units and the activity in the presence of the inhibitor is 0.53 units. The % residual activity is 30.3%. The % inhibition is 100-30.3 = 69.7%.
Following the discussion.
Thank you Prof. Adam B Shapiro for your detailed explanation.
@Pratigya Tripathi, a well illustrated explanation has been given by Dr. Shapiro..Many a time, a lot of people confuse % residual activity with % relative activity. Please take note, there is a difference with reference to the control.
@ adeyemi Oluwadare
I was wonderig if you'd explain about the difference between residual activity and relative activity and their control.
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