Chapter 18, Problem 18.35P

Interpretation Introduction

Interpretation:

The value of the turnover number of the enzyme molecule fumarase which has a single active site has to be determined.

Concept Introduction:

Lineweaver – Burk equation:

The Lineweaver – Burk equation is given below.

  $\frac{1}{R}=\left(\frac{K_M}{R_{\max }}\right)\left(\frac{1}{\left[S\right]}\right)+\frac{1}{R_{\max }}$

Where, $R_{\max }$ is the maximum rate of a reaction, $K_M$ is Michaelis – Menten constant and $\left[S\right]$ is the substrate concentration.

The above equation is in the form of $y=mx+c.$  If $\frac{1}{R}$ is plotted against $\frac{1}{\left[S\right]}$, a straight line with an intercept of $\frac{1}{R_{\max }}$ and a slope of $\frac{K_M}{R_{\max }}$ can be obtained.

A Lineweaver – Burk plot is given below.

Figure 1

The turnover number can be estimated as given below.

  $Turnovernumber=\frac{R_{\max }}{{\left[E\right]}_t}=k_2$