FIGURE 6.
The amenability of a composite reaction by an allosteric modulator can be described by αapp. (A) Hypothetical free energy landscape of the conformational rearrangement that carries (co)-substrate through the membrane and which surpasses a short-lived occluded state (TOcc). The reaction is assumed to be amenable by an allosteric modulator. Shown on top is the corresponding reaction diagram. (B) Equivalent free energy landscape of the reaction in (A). The corresponding reaction scheme is shown on top. The scheme in (A,B) are indistinguishable in their ability to account for the (i) affinity of the modulator for the two stable ground states and (ii) the composite reaction rate both in the absence and presence of the modulator. These are the parameters, which can be measured in experiments.