Lineweaver-Burk plot

When v_o is plotted against [S], it is not always possible to determine when Vmax has been achieved because of the gradual upward slope of the hyperbolic curve at high substrate concentrations. However, if 1/v_o is plotted versus 1/[S], a straight line is obtained (Fig. 1). This plot, the Lineweaver-Burk plot (also called a double-reciprocal plot) can be used to calculate K_m and V_max as well as to determine the mechanism of action of enzyme inhibitors.

Figure 1 Lineweaver-Burk plot. vo = initial reaction velocity; V_max = maximal velocity; K_m = Michaelis constant; [S] = substrate concentration.

The equation describing the Lineweaver-Burk plot is:

where the intercept on the x axis is equal to − 1/K_m, and the intercept on the y axis is equal to 1/V_max. [Note: The slope = K_m/V_max.]