MCB 123 Homework 3
You are observing the enzymatic conversion of S to P in the presence of various concentrations of inhibitor I. Use DELTAGRAPH, Excel or similar plotting program to:
- Print double reciprocal plots (best done as an overlay) and linear fits for each inhibitor concentration. Also include slope and y-intercept replots. What kind of inhibition is being observed? State your findings for these plots and make your reasoning clear. Include any calculations or plots that support your findings. Note that the data are ideal – your fits should be very close to perfect. R2 should be >0.99 in pretty much all cases (depending on your rounding).
- Determine ALL constants defining the system for the substrate and inhibitor by analyzing the double reciprocal plot and any replots you may have to do. Print these replots out and clearly label the axes (you may do this by hand if necessary). For full credit, clearly show how you derive the constants.
Velocities are in nM/min
|
[S] (mM) |
[I] 0 mM |
0.15 mM |
0.25 mM |
0.50 mM |
1.00 mM |
2.00 mM |
4.00 mM |
|
0.500 |
4.71 |
3.51 |
3.03 |
2.32 |
1.68 |
1.21 |
0.92 |
|
0.667 |
6.00 |
4.50 |
3.90 |
3.00 |
2.18 |
1.58 |
1.20 |
|
1.000 |
8.25 |
6.28 |
5.48 |
4.25 |
3.12 |
2.27 |
1.73 |
|
2.000 |
13.20 |
10.40 |
9.19 |
7.29 |
5.46 |
4.04 |
3.11 |
|
10.000 |
25.38 |
21.82 |
20.09 |
17.03 |
13.67 |
10.70 |
8.58 |
