# Lineweaver-Burk plot

In biochemistry, the Lineweaver-Burk plot (or double reciprocal plot) is a graphical representation of the Lineweaver-Burk equation of enzyme kinetics, described by Hans Lineweaver and Dean Burk in 1934[1].

## Derivation

The plot provides a useful graphical method for analysis of the Michaelis-Menten equation:

Taking the reciprocal gives

where V is the reaction velocity, Km is the Michaelis-Menten constant, Vmax is the maximum reaction velocity, and [S] is the substrate concentration.

## Use

The Lineweaver-Burk plot was widely used to determine important terms in enzyme kinetics, such as Km and Vmax before the wide availability of powerful computers and non-linear regression software, as the y-intercept of such a graph is equivalent to the inverse of Vmax; the x-intercept of the graph represents -1/Km. It also gives a quick, visual impression of the different forms of enzyme inhibition.

The double reciprocal plot distorts the error structure of the data, and it is therefore unreliable for the determination of enzyme kinetic parameters. Although it is still used for representation of kinetic data[2], non-linear regression or alternative linear forms of the Michaelis-Menten equation such as the Eadie-Hofstee plot are generally used for the calculation of parameters[3].

When used for determining the type of enzyme inhibition, the Lineweaver-Burk plot can distinguish competitive, noncompetitive and uncompetitive inhibitors. Competitive inhibitors have the same y-intercept as uninhibited enzyme (since Vmax is unaffected by competitive inhibitors the inverse of Vmax also doesn't change) but there are different slopes and x-intercepts between the two data sets. Noncompetitive inhibition produces plots with the same x-intercept as uninhibited enzyme (Km is unaffected) but different slopes and y-intercepts. Uncompetitive inhibition causes different intercepts on both the y and x axes but the same slope.

## See also

Double Reciprocal Plot

## Reference

1. ^ Lineweaver, H; and Burk, D. (1934). "The Determination of Enzyme Dissociation Constants". Journal of the American Chemical Society 56: 658—666.
2. ^ Serap Doğan, Pınar Turan and Mehmet Doğan (December 2006). "Some kinetic properties of polyphenol oxidase from Thymbra spicata L. var. spicata". Process Biochemistry 41 (12): 2379-2385. doi:10.1016/j.jchromb.2006.07.006.
3. ^ Greco, W. R. and Hakala, M. T., (1979,). "Evaluation of methods for estimating the dissociation constant of tight binding enzyme inhibitors,". J. Biol. Chem., 254,: 12104-12109,.

## External links

• NIH guide, enzyme assay development and analysis
Biochemistry is the study of the chemical processes in living organisms.[1] The word "biochemistry" comes from the Greek word βιοχημεία biochēmeia, which means "the chemistry of life.
..... Click the link for more information.
Enzyme kinetics is the study of the rates of chemical reactions that are catalysed by enzymes. The study of an enzyme's kinetics provides insights into the catalytic mechanism of this enzyme, its role in metabolism, how its activity is controlled in the cell and how drugs and
..... Click the link for more information.
Dean Burk (March 21, 1904 - Oct. 6 1988) was an American biochemist: a co-discoverer of biotin, medical researcher, and a cancer researcher at the Kaiser Wilhelm Institute and the National Cancer Institute .

He entered the University of California at Davis at the age of 15.
..... Click the link for more information.
Michaelis-Menten kinetics describes the kinetics of many enzymes. It is named after Leonor Michaelis and Maud Menten. This kinetic model is valid only when the concentration of enzyme is much less than the concentration of substrate (i.e.
..... Click the link for more information.
Michaelis-Menten kinetics describes the kinetics of many enzymes. It is named after Leonor Michaelis and Maud Menten. This kinetic model is valid only when the concentration of enzyme is much less than the concentration of substrate (i.e.
..... Click the link for more information.
In chemistry, concentration is the measure of how much of a given substance there is mixed with another substance. This can apply to any sort of chemical mixture, but most frequently the concept is limited to homogeneous solutions, where it refers to the amount of
..... Click the link for more information.
In statistics, nonlinear regression is the problem of inference for a model

based on multidimensional , data, where is some nonlinear function with respect to unknown parameters θ.
..... Click the link for more information.
In two-dimensional coordinate geometry, the y-intercept is the point where the graph of a function or relation intercepts the y-axis of the coordinate system.

In other words, the y-intercept of a function is the point at which it intersects the line
..... Click the link for more information.
root (or a zero) of a complex-valued function is a member of the domain of such that vanishes at , that is,

In other words, a "root" of a function is a value for that produces a result of zero ("0").
..... Click the link for more information.
Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides.
..... Click the link for more information.
Michaelis-Menten kinetics describes the kinetics of many enzymes. It is named after Leonor Michaelis and Maud Menten. This kinetic model is valid only when the concentration of enzyme is much less than the concentration of substrate (i.e.
..... Click the link for more information.
In biochemistry, an Eadie-Hofstee diagram (also Woolf-Eadie-Augustinsson-Hofstee or Eadie-Augustinsson plot) is a graphical representation of enzyme kinetics in which reaction velocity is plotted as a function of the velocity vs.
..... Click the link for more information.
Michaelis-Menten kinetics describes the kinetics of many enzymes. It is named after Leonor Michaelis and Maud Menten. This kinetic model is valid only when the concentration of enzyme is much less than the concentration of substrate (i.e.
..... Click the link for more information.
In biochemistry, an Eadie-Hofstee diagram (also Woolf-Eadie-Augustinsson-Hofstee or Eadie-Augustinsson plot) is a graphical representation of enzyme kinetics in which reaction velocity is plotted as a function of the velocity vs.
..... Click the link for more information.
In biochemistry, a Hanes-Woolf plot is a graphical representation of enzyme kinetics in which the ratio of the initial substrate concentration [S] to the reaction velocity v is plotted against [S].
..... Click the link for more information.
Proteins are large organic compounds made of amino acids arranged in a linear chain and joined together by peptide bonds between the carboxyl and amino groups of adjacent amino acid residues.
..... Click the link for more information.
Enzymes are proteins that catalyze (i.e. accelerate) chemical reactions.[1] In enzymatic reactions, the molecules at the beginning of the process are called substrates, and the enzyme converts them into different molecules, the products.
..... Click the link for more information.
The active site of an enzyme contains the catalytic and binding sites. The structure and chemical properties of the active site allow the recognition and binding of the substrate.
..... Click the link for more information.
In biochemistry, allosteric regulation is the regulation of an enzyme or protein by binding an effector molecule at the protein's allosteric site (that is, a site other than the protein's active site).
..... Click the link for more information.
In biochemistry, a binding site is a region on a protein, DNA, or RNA to which specific other molecules and ions — in this context collectively called ligands, or more specifically, protein ligands — form a chemical bond.
..... Click the link for more information.
A catalytically perfect enzyme or kinetically perfect enzyme is an enzyme that catalyzes so efficiently, that almost every time enzyme meets its substrate, the reaction occurs.
..... Click the link for more information.
Coenzymes are small organic non-protein molecules that carry chemical groups between enzymes. They are substrates for enzymes and do not usually form a permanent part of the enzymes' structures.
..... Click the link for more information.
EC1 Oxidoreductases/list - EC2 Transferases/list - EC3 Hydrolases/list - EC4 Lyases/list - EC5 Isomerases/list - EC6 Ligases/list
..... Click the link for more information.
Cooperativity is a phenomenon in biology displayed by enzymes or receptors that have multiple binding sites. This is referred to as cooperative binding. We also see cooperativity in large chain molecules made of many identical (or nearly identical) subunits (such as DNA, proteins,
..... Click the link for more information.
Enzyme Commission number (EC number) is a numerical classification scheme for enzymes, based on the chemical reactions they catalyze. As a system of enzyme nomenclature, every EC number is associated with a recommended name for the respective enzyme.
..... Click the link for more information.
Enzyme catalysis is the catalysis of chemical reactions by specialized proteins, enzymes. Catalysis of biochemical reactions in the cell is vital due to the very low reaction rates of the uncatalysed reactions.
..... Click the link for more information.
Enzyme inhibitors are molecules that bind to enzymes and decrease their activity. Since blocking an enzyme's activity can kill a pathogen or correct a metabolic imbalance, many drugs are enzyme inhibitors. They are also used as herbicides and pesticides.
..... Click the link for more information.
Enzyme kinetics is the study of the rates of chemical reactions that are catalysed by enzymes. The study of an enzyme's kinetics provides insights into the catalytic mechanism of this enzyme, its role in metabolism, how its activity is controlled in the cell and how drugs and
..... Click the link for more information.
Michaelis-Menten kinetics describes the kinetics of many enzymes. It is named after Leonor Michaelis and Maud Menten. This kinetic model is valid only when the concentration of enzyme is much less than the concentration of substrate (i.e.
..... Click the link for more information.
This article is a list of enzymes, sorted by their respective sub-categories and EC number.

See also:
• List of EC numbers
• List of EC numbers (EC 1)
• List of EC numbers (EC 2)
• List of EC numbers (EC 3)
• List of EC numbers (EC 4)
• List of EC numbers (EC 5)

..... Click the link for more information.

This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.