Complex equilibrium calculations enzyme kinetics

The kinetic investigation of enzymic reactions and suitable non-enzymic standard reactions permits, as just described, the numerical calculation of measures of enzyme catalytic power. These measures are ratios of rate constants and they correspond to equilibrium constants for reactions of free enzyme or enzyme complexes with the transition state for the standard reaction to generate complexes of the enzyme with various transition states along the enzymic reaction pathway, sometimes with liberation of other ligands (see the examples above). 

In the following sections the extension of Eq. (18) to more complex reaction schemes is described. Again the rapid equilibrium assumption is used to show how more complex rate equations are derived from simple Michaelis-Menten kinetics. Attention is focused on some typical rate equations that are useful to describe enzyme kinetics with respect to a desired process optimization. The whole complexity of enzyme kinetics is of importance for a basic understanding of the enzyme mechanism, but it is not necessary for the fitting of kinetic data and the calculation of reactor performance. 

The results obtained from Lineweaver-Burk plots, are used for calculation of kinetic constants. The secondary plots of the slopes and intersects vs. activator concentrations are not linear (data not shown), but the reciprocal of the change in slope and intercept (Aslope and Ainiercept) that are determined by subtracting the values in the paesence of activator from that in its absence, are hnear. The intercepts of a plot 1/Aslope and 1/Airtercept 1/ [Al ] on 1/A axis, and intercepts of both plots on l/[ Al ] axis are used for calculating equilibrium constants Kms and Kma for dissociation of formed binary enzyme-activator (Al ) and ternary enzyme activator- substrate complexes (Figure 4). The calculated values for constants are (0.904 + 0.083) mM and (8.56 + 0.51) mM, respiectively. 

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