Figure 2

Four-step linear pathway with Michaelis-Menten kinetics. A) Schematic representation of a four-step linear pathway coupled with enzyme dynamics. It consists in four enzymatic reactions, where the substrate (S ₁) is converted into the product (S ₄). B) Metabolite dynamics, expression rates and enzyme activation profiles that minimize the time needed to reach a given steady state and the corresponding enzyme consumption, see Equation (16). C) Pareto front obtained by minimizing the time and the enzyme cost needed to reach a certain amount of product using Equation (23). D) Enzyme profiles for the points P ₁, P ₂ and P ₃ of the Pareto front using ρ=120 steps with fixed duration. Enzyme and metabolite concentrations are expressed in concentration units (mM) and time in seconds (s).