ABSTRACT
Chapter 15 is rather difficult to understand. However, if you are able to extract the essentials with a clear sense of ‘what should be done for model-building in the future’, you are well off.
Chapter 15 begins with a brief account of the origin of the allosteric model and its development by MonodWyman-Changeux, the MWC model. In sub-chapter 15.3, I go through the classic description of the MWC model in a homotropic setting with a single type of ligand. In Sections 15.3.415.3.6, as a novelty, I demonstrate how the functional aspect of the MWC model has been diverted in a spurious direction by the original MWC paper, and instead I offer an operative formulation for the functional aspect of the MWC model; a formulation which should be followed in order to handle catalytic activity in enzymes and molecular movement by co-transporters in the spirit of a genuine allosteric model. Hopefully, Sections 15.3.415.3.6 will perplex the reader followed by enlightenment. At the outset, heterotropy is briefly introduced by Eq. 15c in Section 15.3.4. The MWC model in a heterotropic setting with at least two different types of ligands is dealt with in sub-chapter 15.4. This is followed in subchapter 15.5 by a short account on the term ‘desensitization’ as used by two schools. Sub-chapter 15.6 presents a short discussion of other allosteric models such as the Koshland et al. reaction schemes, KNF models, in line with the Hill-Adair-Pauling tradition of varying interactions between subunits interactions. Although these schemes are less restrictive and more comprehensive than the MWC model, working with them is more difficult. In sub-chapter 15.8, amongst other model expansions, I present a Pascal extension of the modified Hill equation, offer a comparison between the MWC model and the Katz and Thesleff two-state model, and further specify what differentiates the MWC model from other models. I conclude with a section on how to model in the future. Sub-chapter 15.9 is a brief summary on which theoretical tools to choose in order to evaluate experimental equilibrium effects.
