FIG. 5.

The degree of saturation of the reaction processes of Aβ40 kinetics: blue for secondary nucleation; purple for elongation, and green for primary nucleation. (a) The concentrations at which the different reaction processes are 50% saturated. At these concentrations, saturation effects reduce the overall rates by 50%. (b) The fractional occupation of the catalytic surface for each reaction process over the range of monomer concentrations studied here. This makes a suitable definition for the degree of saturation of each process. Secondary nucleation is essentially fully saturated over all concentrations of interest, whereas elongation is largely unsaturated. Primary nucleation is fully saturated at the higher end of the range of concentrations studied. Where the fractional occupation is small, dissociation dominates over binding; where it is large, binding dominates over dissociation.