Fig. 3: Relationship between thermodynamic landscapes and enzymatic activity.
From: Thermodynamic principle to enhance enzymatic activity using the substrate affinity
Three thermodynamic landscapes are shown in A. Their corresponding Michaelis-Menten plots are shown in B. The \({K}_{m}\) values are indicated as vertical dashed lines in B. Increasing the driving force of the first step increases the activity at low substrate concentrations but lowers the activity at high substrate concentrations. Therefore, the thermodynamic landscape of an optimum enzyme depends on the substrate concentration ([S]). The free energies of the enzyme-substrate complex (\(\Delta {G}_{1}\)) were −25, −20, and −15 kJ/mol for the black, blue, and red lines, respectively, and that of the total reaction (\(\Delta {G}_{T}\)) was −40 kJ/mol. All numerical simulations in this study were performed at \([{{{{{{\rm{E}}}}}}}_{{{{{{\rm{T}}}}}}}]\) = 0.01 µM, \({k}_{1}^{0}={k}_{2}^{0}=1\) (1/µM/s and 1/s units, respectively), and \({\alpha }_{1}={\alpha }_{2}=0.5\) unless otherwise noted. See the python code in Supplementary Data 2 for details.
