Question

In contrast to ibuprofen, aspirin is an irreversible inhibitor of PGH₂ synthase, reacting with a Ser residue in the active site. You have incubated 5 µM enzyme with 1 mM aspirin and have found that 85% of the enzyme was inactivated in 30 minutes.

I found the pseudo first-order rate constant to be 0.063 min^-1 and the second order rate constant is 0.0378 µM/min.

C) Suppose you wanted to use 5 mM aspirin and inactivate 99% of the enzyme. For how long should you allow the reaction to proceed?

D) Suppose that you incubate 1 µM enzyme with 1 mM aspirin for 30 minutes. Would you expect more or less that 85% of the enzyme to be inactivated? Explain your reasoning.

E) Suppose that you incubate 1 mM enzyme with 1 mM aspirin for 30 minutes. Would you expect more or less than 85% of the enzyme to be inactivated? Explain your reasoning.

Answer 1