You measure the kinetics of an enzyme e as a function of s

Question

 1. You measure the kinetics of an enzyme E as a function of [S] and plot the following Lineweaver-Burke plot.

a)The enzyme concentration is kept constant at 1μM (10^-6 M). From these data, determine v_max, K_M, k_cat and the turnover for the enzyme. Justify your answer clearly.

b)Now you study enzyme inhibition by measuring the kinetics in the presence of10 mMinhibitor A or B (in separate experiments, of course). The Lineweaver-Burke plots are in the figure to the right.

From these data, determine the type of inhibition for A and for B.

Justify your answer.

c) Illustrate with a drawing how the inhibition works for each inhibitor. 

d) Which of the two inhibitors is more effective at high substrate concentrations? 

7. Thymidylate synthase catalyzes the synthesis of thymidine. Glu 60, Cys 198 and Arg 218 are three residues at the active site. The reaction mechanism is shown below.

a.   Which mode of enzymatic catalysis is exemplified by each residue? Write the name and number of the residue next to the type of catalysis.a.   Which of the following mutations is likely to produce an active enzyme: Glu 60 àThr, Cys 198àVal, Arg  218àLys?

Explain your answer.

b. Fluorodeoxyurydilate monophosphate (FdUMP) is an irreversible inhibitor of this enzyme (used in chemotherapy).

What is the difference between reversible and irreversible inhibition and how could you tell the difference experimentally?

Attachment:- P.Set Chapters 8 and 9 .docx