Search results
Results from the WOW.Com Content Network
Competitive inhibition can be overcome by adding more substrate to the reaction, which increases the chances of the enzyme and substrate binding. As a result, competitive inhibition alters only the K m, leaving the V max the same. [3] This can be demonstrated using enzyme kinetics plots such as the Michaelis–Menten or the Lineweaver-Burk plot.
Effects of different types of inhibition on the double-reciprocal plot. When used for determining the type of enzyme inhibition, the Lineweaver–Burk plot can distinguish between competitive, pure non-competitive and uncompetitive inhibitors. The various modes of inhibition can be compared to the uninhibited reaction.
It can be recognized by two observations: first, it cannot be reversed by increasing the substrate concentration , and second, linear plots show effects on and , seen, for example, in the Lineweaver–Burk plot as parallel rather than intersecting lines. It is sometimes explained by supposing that the inhibitor can bind to the enzyme-substrate ...
The plot of against has often been called a "Michaelis–Menten plot", even recently, [7] [8] [9] but this is misleading, because Michaelis and Menten did not use such a plot. Instead, they plotted v {\displaystyle v} against log a {\displaystyle \log a} , which has some advantages over the usual ways of plotting Michaelis–Menten data.
Two equations listed below that are referred to as non-competitive substrate inhibition and competitive substrate inhibition models respectively by Shuler and Michael in Bioprocess Engineering: Basic Concepts. Note that the Haldane equation above is a special case of the following non-competitive substrate inhibition model, where KI >>Ks. [1]
When a non-competitive inhibitor is added the Vmax is changed, while the Km remains unchanged. According to the Lineweaver-Burk plot the Vmax is reduced during the addition of a non-competitive inhibitor, which is shown in the plot by a change in both the slope and y-intercept when a non-competitive inhibitor is added. [8]
In enzyme kinetics, a secondary plot uses the intercept or slope from several Lineweaver–Burk plots to find additional kinetic constants. [1] [2]For example, when a set of v by [S] curves from an enzyme with a ping–pong mechanism (varying substrate A, fixed substrate B) are plotted in a Lineweaver–Burk plot, a set of parallel lines will be produced.
The Schild plot of a reversible competitive antagonist should be a straight line, with linear gradient, whose y-intercept relates to the strength of the antagonist. In pharmacology , Schild regression analysis , based upon the Schild equation , both named for Heinz Otto Schild , are tools for studying the effects of agonists and antagonists on ...