**A**. A non-cooperative, bell-shaped ternary complex dose-response curve (black curve) can be explained by a sigmoidal “formation” term (red curve) and a reversed sigmoidal “autoinhibition” term (blue curve). When both of these curves are plateaued at [B]_{t,max}, the left side of the ternary complex curve (black curve) is described by the A–B binding event (TF_{50}), whereas the right side is described by the B–C binding event (TI_{50}). **B**. Non-cooperative systems can be divided into four quadrants, which enable simplification of [ABC]_{max}, [B]_{t,max}, TF_{50}, and TI_{50} equations. Regarding the height (y-axis, or [ABC]_{max}), ternary complex does not form appreciably in Quadrants I and II but forms quantitatively in Quadrants III and IV. The width and position (x-axis, or TF_{50}, TI_{50}, and [B]_{t,max}) of these curves are controlled by either the binding constants (Quadrant I), the terminal species concentrations (Quadrant IV), or a combination of both (Quadrants II and III). (Red indicates A–B binding event; blue indicates B–C binding event)

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