Scalable Rule-Based Modelling of Allosteric Proteins and Biochemical Networks
Figure 2
Allostery makes macromolecular assembly robust and controllable.
(A) Effect of allostery on macromolecular assembly when a linker component is over-expressed. Each curve shows the equilibrium concentration of the XAY trimer against the total amount of A. The total amount of X and Y was unity, while KRT and the affinities of X and Y to each conformation of A (KRX, KRY, KTX, KTY) were chosen to yield a desired value of θ and with KX = KY = 1. Inset: A coarse-grained version of the divalent protein model of Figure 1C sums over the two possible conformations of A and shows that with KX, KY and the concentrations of X and Y held constant, the efficacy of assembly depends only on the cooperativity parameter θ. (B) Regulation of cooperativity and assembly. The value of θ depends on the other parameters of the model through Equation 1, which is plotted against KRT on one axis and ΓX and ΓY (assumed equal) on the other. Increasing ΓX and ΓY always increases cooperativity, however θ has a maximum value as KRT is changed.