In the enzyme kinetics experiment, you obtain the following results, using an ex
ID: 66467 • Letter: I
Question
In the enzyme kinetics experiment, you obtain the following results, using an excess of pyruvate: Lactate dehydrogenase is a tetrameric enzyme. Based on the data above, is there any evidence of cooperative substrate binding to this tetramer? Determine the value of V_max and of the Hill coefficient based on the data above. Provide an equation that relates the fractional saturation of the enzyme (Y = enzyme bound to substrate / total enzyme) to V_max and to the initial reaction rate. Based on your experimental data, generate a Hill plot for the enzyme you produced. What does the slope of this plot represent?Explanation / Answer
a. Analysing the above data, only negative cooperative substrate binding would be evidenced with this tetramer.
b. Convert both colums of data by dividing 1 by each number
The linear equation y = 2.8983x - 5.9489
1/Vmax is the y-intercept, whihc is 5.9489. So Vmax = 1/5.9489 = 0.1680 µmol/min/ml
K0.5 = 0.0840µmol
The x intercept is -1/km. So in the above equation. 0=2.8983(-1/Km)-5.9489. so Km = 2.8983/5.9489 or 0.4871mM
Michaelis-Menten equation-interactive graph
c.The fractional saturation is defined as the fraction of sites occupied by the ligand:
= number of sites occupied by the ligand / total number of sites
If S is a substrate of the enzyme, which transforms S into a product T, then the kinetics rate v of appearance of product T is v = d[P] / dt = vmax
d. The hill plot generated shows a negative cooperative substrate binding to enzyme.
20 58.82353 10 11.76471 5 2.590674 3.333333 1.30719 2.5 0.892061 2 0.766284 1.666667 0.68918 1.25 0.4 1 0.59988 0.833333 0.587544