Lineweaver–Burk Plot Overview
- The Lineweaver-Burk equation of enzyme kinetics is represented graphically by the Lineweaver-Burk Plot (also known as the double reciprocal plot), which was first introduced by Dean Burk and Hans Lineweaver in 1934.
- It is difficult to predict Vmax and, consequently, Km from a hyperbolic plot since Vmax is reached at an infinite substrate concentration.
- Due to this challenge, Lineweaver and Burk converted the Michaelis-Menten equation into an equation for a straight line.
- The Michaelis-Menten equation is used to derive this plot, which is shown as:
Where Vmax is the maximum reaction velocity, [S] is the substrate concentration, Km is the Michaelis-Menten constant, and V is the reaction velocity (or reaction rate).
- It results in a straight line with intercepts that are equal to Km/Vmax on the x-axis and 1/Vmax on the y-axis. Km/Vmax determines the line’s slope to be equal.
- By measuring V0 at various substrate concentrations, it is possible to experimentally calculate Vmax and Km. Then 1/V0 is plotted versus 1/[S] using a double reciprocal or Lineweaver-Burk plot.
- A Lineweaver-Burk plot can be used to discriminate between competitive and non-competitive reversible enzyme inhibitors.
- This method is effective for figuring out how an inhibitor interacts with an enzyme.
- If V0 is measured when a fixed concentration of inhibitor is present and multiple substrate concentrations are present, competitive inhibition may be identified using a Lineweaver-Burk plot.
- The Lineweaver-Burk figure shows that a competitive inhibitor raises the slope of the line, changes the intercept on the x-axis (because Km is raised), but does not affect the intercept on the y-axis (since Vmax remains constant).
- Lineweaver-Burk plots may also be used to identify noncompetitive inhibition, since it affects the intercept on the y-axis (because Vmax is lowered) and increases the slope of the experimental line while maintaining the intercept on the x-axis (since Km remains constant).
Uses of Lineweaver–Burk Plot
- Prior to widespread access to powerful computers and nonlinear regression software, it was used to calculate crucial enzyme kinetic parameters like Km and Vmax.
- Quickly conveys a picture of the many types of enzyme inhibition.
- David Hames and Nigel Hooper (2005). Biochemistry. Third ed. Taylor & Francis Group: New York.
- Smith, C. M., Marks, A. D., Lieberman, M. A., Marks, D. B., & Marks, D. B. (2005). Marks’ basic medical biochemistry: A clinical approach. Philadelphia: Lippincott Williams & Wilkins.