What Is A Lineweaver Burk Graph
LINEWEAVER-BURK PLOT A graph of the double reciprocal equation is also called a Lineweaver-Burk, 1/Vo vs 1/[S]. The y intercept is 1/VMAX; the x-intercept is 1/ KM; and the slope is KM/VMAX. Lineweaver Burk graphs are particularly useful for analyzing how enzyme kinematics change in the presence of inhibitors, competitive, noncompetitive, or a mixture of the two. There are three reversible inhibitors: competitive, uncompetitive, and noncompetitive. They can be plotted on double reciprocal plot. Competitive inhibitors are molecules that look like substrates and they bind to active site and slow down the reactions. Therefore, competitive inhibitors increase Km value (decrease affinity, less chance the substrates can go to active site), and VMAX stays the same. On double reciprocal plot, competitive inhibitor swifts the x-axis (1/[s]) to the right towards zero compared to the slope with no inhibitor present. Uncompetitive inhibitors can bind close to the active site but don't occupy the active site. As a result, uncompetitive inhibitors lower Km (increase affinity) and lower VMAX. On double reciprocal plot, x-axis (1/[s]) is shifted to the left and up on the y-axis (1/V) compared to the slope with no inhibitor. Noncompetitive inhibitors are not bind to the active site but somewhere on that enzyme which changes its activity. It has the same Km but lower VMAX to those with no inhibitors. On the double reciprocal plot, the slope goes higher on y-axis (1/V) than the one with no inhibitor.
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Eadie-Hofstee
Eadie-Hofstee