Binding mechanisms, multiple

In some cases, an inhibitor can bind to more than one site on an enzyme protein, with inhibition resulting from binding at multiple sites. Binding affinities at the two (or more) sites may be different, and mechanisms of inhibition may be dilferent for example, high-affinity inhibition might occur through an allosteric site and lower affinity inhibition through the active site. Analysis of such systems is complex and may require a combination of several of the approaches outlined later. 

Grassi, M., and Daquino, V. (2005). 113Cd NMR and fluorescence studies of multiple binding mechanisms of Cd(II) by the Suwannee River fulvic acid. Ann. Chim-Rome 95, 579-591. 

In summary, C. albicans possesses a broad panel of molecules involved in adherence with different binding mechanisms which can function independently. Many of these molecules, such as members of the Als family, Intlp, Hwplp, appear to be specific for C. albicans and are not found in other yeasts. Secreted aspartic proteinases, which are also a particularity of C. albicans are additionally involved in adherence. Their multiple roles in virulence will be discussed below. 

The mechanism of molecular recognition and chiral discrimination of cellulose-and amylose-derived chiral selectors is difficult to study due to the complexity of the macromolecule and their multiple binding sites. However, some knowledge of binding mechanisms exist for selected selectands from NMR spectroscopy ] 165.166], molec-... 

It is apparent from Scheme 4.3 that the inhibitor cannot only compete with substrate for binding to the enzyme but bind to an enzyme molecule that subsequently binds a substrate molecule also or to an enzyme-substrate complex to affect catalytic turnover. These multiple binding mechanisms help explain the effects of mixed inhibition on both Vmax and K. The effects of mixed inhibition on the velocity of the reaction can be described by the following mixed inhibition equation (Eq. 4.15) ... 

This is the general equation for multiple equilibrium (X and 11 are respective symbols for summation and multiplication) that describes the binding of ligand molecules to the biomacromolecules with multiple sites. However, there are so many adjustable parameters in this general equation, which is more revealing about the binding mechanism if the experimental data can be fitted to simplified models by more restrictive equations with fewer adjustable parameters. These models will be considered. 

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