Lineweaver-Burke plots

A plot of 1/v versus 1/[S], which is called a double reciprocal, or Lineweaver-Burk plot, is a straight line with a slope of Km/Vmax) a y-intercept of 1/Vmax> and an x-intercept of-l/Km (Figure 13.11). 

The three reversible mechanisms for enzyme inhibition are distinguished by observing how changing the inhibitor s concentration affects the relationship between the rate of reaction and the concentration of substrate. As shown in figure 13.13, when kinetic data are displayed as a Lineweaver-Burk plot, it is possible to determine which mechanism is in effect. 

Effect of the concentration of inhibitor on the Lineweaver-Burk plots for (a) competitive inhibition, (b) noncompetitive inhibition, and (c) uncompetitive inhibition. The inhibitor s concentration increases in the direction shown by the arrows. 

Lineweaver-Burk plot a graphical means for evaluating enzyme kinetics, (p. 638)... 

Lineweaver-Burk Plot (Rate of reaction m. s/kmol)... 

Using the developed eomputer program PROGl, the model equation 1/Y = A + B 1/X represents the Lineweaver-Burk plot represented by Equation 11-17 as ... 

Figure 11-5 shows the Lineweaver-Burk plot of 1/v versus 1/Cj,. 

Figure 11-5. Double reoiprooal (Lineweaver-Burk) plot to determine and kg...

Competitive and non-eompetitive inhibitions are easily distinguishable from the Lineweaver-Burk plot. In the ease of eompetitive inhibitors, the intereept on tlie 1/Cg axis inereases while tlie intereept of tlie 1/v axis remains unehanged by the addition of the inhibitor. Conversely, with a non-eompetitive inhibitor, only the 1/v axis intereept inereases. The effeet of eompetitive inhibitors ean be reversed by inereasing the substrate eoneentration. Where the enzyme or the enzyme substrate eomplex is made inaetive, a non-eompetitive inhibitor deereases of the enzyme, but remains eonstant. 

Lineweaver-Burk plot Method of analyzing kinetic data (growth rates of enzyme catalyzed reactions) in linear form using a double reciprocal plot of rate versus substrate concentration. 

The Michaelis-Menten equation is, like Eq. (3-146), a rectangular hyperbola, and it can be cast into three linear plotting forms. The double-reciprocal form, Eq. (3-152), is called the Lineweaver-Burk plot in enzyme kinetics. ... 

Pure noncompetitive inhibition occurs if Ki = Ki. This situation is relatively uncommon the Lineweaver-Burk plot for such an instance is given in Eigure 14.15. Note that K is unchanged by I (the x-intercept remains the same, with or without I). Note also that Tmax decreases. A similar pattern is seen if the amount of enzyme in the experiment is decreased. Thus, it is as if I lowered [E],... 

FIGURE 14.16 Lineweaver-Burk plot of mixed noncompetitive inhibition. Note that both intercepts and the slope change in the presence of I. (a) When Ki is less than Ki (b) when Ki is greater than Ki. ... 

FIGURE 14.18 Single-displacement bisubstrate mechanism. Double-reciprocal plots of the rates observed with different fixed concentrations of one substrate (B here) are graphed versus a series of concentrations of A. Note that, in these Lineweaver-Burk plots for singledisplacement bisubstrate mechanisms, the lines intersect to the left of the 1/v axis. 

First draw both Lineweaver-Burk plots and Hanes-Woolf plots for the following a Monod-Wyman-Changeux allosteric K enzyme system, showing separate curves for the kinetic response in (1) the absence of any effectors (2) the presence of allosteric activator A and (3) the presence of allosteric inhibitor I. Then draw a similar set of curves for a Monod-Wyman-Changeux allosteric Uenzyme system. 

This is referred to as a double reciprocal or lineweaver Burk plot. From this linear plot, Kd = slope/intercept and the 1 /intercept = Bmax. Finally, a linear plot can be achieved with... 

The competitive and non-competitive inhibitors are easily distinguished in a Lineweaver-Burk plot. The competitive inhibitor intercepts on the Mv axis whereas the non-competitive inhibitor intercepts on the 1/5 axis. The reaction of inhibitors with substrate can be assumed as a parallel reaction while the undesired product is formed along with desired product. The reactions are shown as ... 

Plot both sets of data as a Lineweaver-Burk plot for competitive inhibition (see Fig. 

According to this expression, a plot of 1/v, versus l/[SJo will yield a straight line if the data follow the Michaelis-Menten mechanism. This line has a slope given by Km/Vmax, a y intercept of 1/Vmax, and an x intercept of -1 fKm. This is also illustrated in Fig. 4-7. Again, this treatment is valid when Eq. (4-107) applies whether or not the catalyst is an enzyme. The Lineweaver-Burk plot, Fig. 4-lb, is convenient for visualization but statistically unreliable for data fitting the form in Eq. (4-107) should be used for numerical analysis. 

Equation (35) is the equation for a straight line, 7 = ax + b, wherey= l/v[andx= 1/[S]. Aplot of 1/v as j/as a function of 1/[S] as x therefore gives a straight line whose jy intercept is 1/l iax and whose slope is KJV. Such a plot is called a double reciprocal or Lineweaver-Burk plot (Figure 8-5). Setting thej/ term of equation (36) equal to zero and solving for x reveals that the x intercept is — IK. ... 

Figure 8-5. Double reciprocal or Lineweaver-Burk plot of 1/V versus 1/[S] used to evaluate and 1/max-...

Figure 8-9. Lineweaver-Burk plot of competitive inhibition. Note the complete relief of inhibition at high [S] (ie, low 1 /[S]).

Figure 8-10. Lineweaver-Burk plot for simple noncompetitive inhibition.

Lineweaver-Burk plots [11] over the range 0.1 to 1 mM Paraoxon in 100 mM CHES buffer, pH 9.0. Linear regression analysis for Lineweaver-Bulk plot was performed using SigmaPlot software (Systat Software, USA). 

Fig. 3. Lineweaver-Burk plot analyses for four types of recombinant whole cell biocatalytic reactions.

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