Biochemistry I - Enzyme Inhibition DryLab - Problem Set 7 - Q2

Enzyme Inhibition Kinetics: You can add any concentration of substrate and inhibitor to the reaction tube. The inhibitor concentration is the same for both inhibitor A and inhibitor B. a) Obtain v versus S data with no inhibitor. Both vo values should be the same, since [I]=0. b) Obtain v versus S data with a constant amount of inhibitor. The left vo is for inhibitor 1 and the right vo is for inhibitor 2. You want to add enough inhibitor to show an effect. c) Use the resulting values of vo to calculate 1/vo and 1/[S]; d) Plot the data (both without and with added inhibitor) on a single double reciprocal plot. Submit the plot with your problem set. e) Determine and Vmax's and the slopes of each plot d) What type of inhibitor are these - competitive or mixed? e) Calculate KI, and if appropriate KI' 1. Enter values for [S] and [ I ] in these boxes: [S] = uM [ I ] = uM 2. For the above values of [S] and [I], Calculate vo vo = uM/min (Inh A) vo = uM/min (Inh B) (Each calculated vo value has a small "experimental error" added to it.) Hint: Ignore the data <10% and >90% Vmax when drawing a line. These values will have more relative error and they are not necessary to determine an accurate slope and intercept on the reciprocal plot.