Lineweaver-Burke diagram

The reciprocals of these quantities (n, s) when plotted (Lineweaver-Burk diagram) according to... 

The inhibition constant of adenine is determined using the Dixon diagram and is Kj = 0.63 X 10 M. The Kj, gpp for thymidine rises according to the formula gpp = Kj (1 +1/ Kj). The Kj value calculated from the formula agrees well with the value determined from the graph. The value for adenine is 0.066 mM (determination from the non-linear Lineweaver-Burk diagram. 

Fig. 2.25. The Lineweaver Burk diagram of alginate immobilized CGTase [32].

Fig. 19.6 Lineweaver-Burk diagram for two different enzyme concentrations c fl-...

Note the close analogy with the Lineweaver-Burk form of the simple Michaelis-Menten equation. In a diagram representing MV against MX one obtains a line which has the same intercept as in the simple case. The slope, however, is larger by a factor (1 + YIK-) as shown in Fig. 39.17b. Usually, one first determines and in the absence of a competitive inhibitor (F = 0), as described above. Subsequently, one obtains A" from a new set of experiments in which the initial rate V is determined for various levels of X in the presence of a fixed amount of inhibitor Y. The slope of the new line can be obtained by means of robust regression. 

Fig. 6. Competitive inhibition. The diagram shows the characteristic pattern of Lineweaver-Burk plots intersecting on the ordinate for data obtained with and without an added competitive inhibitor, I.

Calculation of Vmax and Km may occur by nonlinear regression or by linearization, such as the Lineweaver and Burk method. Thereafter, reciprocal values of Vand [S] are plotted in a diagram and Eq. (9.2) is transformed to... 

In order to better understand the form of the enzyme involved in catalysis, a hypothetical enzyme-substrate system will be assayed and interpreted. We will start from the assumption that data are available for vq (initial velocity) as a function of substrate concentration at several pH s, e. g., for the Lineweaver and Burk. The values for Km and V are obtained from the family of straight lines (Fig. 2.32) and plotted against pH. The diagram of = f(pH) depicted in Fig. 2.33a corresponds to Fig. 2.31c which implies that neutral (E ) and positively charged (E + ) enzyme forms are active in binding the substrate. 

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