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# Lineweaver–Burk Plot

## Lineweaver–Burk Plot

• Because Vmax is attained at endless substrate concentration, estimating Vmax and thus Km from a hyperbolic plot is impossible.
• Due to this issue, Lineweaver and Burk modified the MichaelisMenten equation into a straight line equation.
•  The Lineweaver–Burk plot (also known as the double reciprocal plot) is a pictorial depiction of the Lineweaver–Burk equation of enzyme kinetics, which was presented by Hans Lineweaver and Dean Burk in 1934.
• This figure is derived from the Michaelis–Menten equation and is denoted as follows:

where V represents the reaction velocity (reaction rate), Km denotes the Michaelis–Menten constant, Vmax denotes the maximum reaction velocity, and [S] denotes the substrate concentration.

• It produces a straight line with a y-axis intercept of 1/Vmax and an x-axis intercept of Km/Vmax. The slope of the line is equal to Km/Vmax.
• Vmax and Km can be calculated experimentally by measuring V0 at various substrate concentrations. Then, for 1/V0 vs 1/[S], a double reciprocal or Lineweaver–Burk plot is generated. • A Lineweaver–Burk plot can be used to discriminate between competitive and noncompetitive reversible enzyme inhibitors.
• It is an effective method for determining how an inhibitor interacts to an enzyme.
• If V0 is measured at multiple substrate concentrations in the presence of a fixed dose of inhibitor, a Lineweaver–Burk plot can be used to detect competitive inhibition.
• On the Lineweaver–Burk plot, a competitive inhibitor increases the slope of the line and changes the intercept on the x-axis (because Km is increased), but leaves the intercept on the y-axis unaltered (since Vmax remains constant).
• Noncompetitive inhibition can also be identified on a Lineweaver–Burk plot because it raises the slope of the experimental line and changes the intercept on the y-axis (due to a drop in Vmax), but leaves the intercept on the x-axis unaltered (since Km remains constant).

### Uses of Lineweaver–Burk Plot

• Before the widespread availability of powerful computers and non-linear regression software, this method was used to calculate crucial parameters in enzyme kinetics, such as Km and Vmax.
• Provides a rapid graphic representation of the various types of enzyme inhibition.

Lineweaver–Burk Plot Citations

1. David Hames and Nigel Hooper (2005). Biochemistry. Third ed. Taylor & Francis Group: New York.
2. 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.
3. https://en.wikipedia.org/wiki/Lineweaver%E2%80%93Burk_plot

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