Use of inhibitors in elucidating the mechanism of an enzyme
The thick blue line in each plot shows the kinetic behavior in the absence of inhibitor, and the thin blue lines in each plot show the change in behavior for increasing concentrations of the inhibitor.In each plot, the inhibitor’s concentration increases in the direction of the green arrow.-diphenyl oxidase in the absence of an inhibitor.We demonstrate an inverse correlation between these parameters thus demonstrating that competitive inhibition is tightly coupled to the nature of the active site of individual enzyme molecules.Department of Materials Science, Key Laboratory of Automobile Materials of MOE and State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China E-mail: [email protected] College of Chemistry and Chemical Engineering, Key Laboratory of Photonic and Electronic Bandgap Materials, Ministry of Education, Harbin Normal University, Heilongjiang 150025, People's Republic of China E-mail: [email protected] as a paradigm for excellent oxidase mimics by theoretical prediction and experimental implementation.This site stores nothing other than an automatically generated session ID in the cookie; no other information is captured.In general, only the information that you provide, or the choices you make while visiting a web site, can be stored in a cookie.Finally, in uncompetitive inhibition the inhibitor binds to the enzyme–substrate complex, forming an inactive ESI complex.
There are several pathways for the reversible binding of an inhibitor to an enzyme, as shown in Figure \(\Page Index\).For example, the site cannot determine your email name unless you choose to type it.Allowing a website to create a cookie does not give that or any other site access to the rest of your computer, and only the site that created the cookie can read it.An irreversible inhibitor covalently binds to the enzyme’s active site, producing a permanent loss in catalytic efficiency even if we decrease the inhibitor’s concentration.
A reversible inhibitor forms a noncovalent complex with the enzyme, resulting in a temporary decrease in catalytic efficiency.
As shown in Figure 13.14, when we display kinetic data using as a Lineweaver-Burk plot it is easy to determine which mechanism is in effect.