Fig. 4: Thermodynamic profiles of reaction orders R1 and R3 for the biosynthesis of IPDO from leucine.
a, b Thermodynamic calculations of the reaction orders R1 and R3 of a four-step reaction cascade. The standard Gibbs free energy of formation of every non-natural product was estimated by using the group contribution method. c Schematic comparison of reaction driving forces (ΔrG) of three synthetic pathways that starts from the same substrate and end with the same product. We assumed that curve A (red dashed line) stands for a pathway with an ideal thermodynamic profile: the driving forces of all four reactions are identical. Curve B reflects the thermodynamic profile of Route 1 (a) that begins with a strong exergonic reaction with high energy driving force while curve C reflects the thermodynamic profile of Route 3 (b) that begins with a less thermodynamic favorable reaction.
