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Identifying the Better Inhibitor


There are three categories for reversible enzyme inhibitors based on the impact of these inhibitors on Michaelis constant and Maximal Velocity (${ V }_{ max }$). The ${ K }_{ I }$ is equilibrium constant for the dissociation of the enzyme-inhibitor complex.

An enzyme assay was done in the absence as well as the presence of a 1 mM concentration of inhibitor A (red line) and inhibitor B ( blue line).

The velocity was measured at a range of substrate concentrations and the results were used to construct a Lineweaver-Burk plot which is shown.

The y-axis is 1/velocity and the x-axis is 1/[substrate]. Kelly Keenan, Created for Copyright 2016. All rights reserved.

It can be seen from this graph that both inhibitor A and B

the Michaelis constant and

the Maximal Velocity.

Based on this graph, inhibitor A and B are

inhibitors for this enzyme.

is the better inhibitor and has the

value for${ K }_{ I }$ .