. 2018 Mar 8;140(11):3854–3857. doi: 10.1021/jacs.8b00251

Table 1. Barriers for Nonenzymatic Deprotonation of GAP, and for the TIM-Catalyzed Deprotonation of GAP, GA, and GA·HP_i, at 25 °C^a.

Substrate	k_cat (s^–1)^b	k_cat/K_M (M^–1 s^–1)^b	ΔG^‡_exp (kcal·mol^–1)^c	ΔG^‡_calc (kcal·mol^–1)^c	ΔG⁰_calc (kcal·mol^–1)^c
CH₃CH₂CO₂^–+ GAP^d	N.A.	N.A.	24.0	24.1 ± 0.2	16.1 ± 0.2
GA	N.A.	0.07	N.A.	15.0 ± 2.4	6.0 ± 2.8
GA·HP_i	N.A.	64	N.A.	15.5 ± 3.5	4.8 ± 4.2
GAP	2100	8.4 × 10⁶	12.9	12.9 ± 0.8	2.5 ± 0.9

N.A., not available.

Kinetic parameters from ref (11).

The calculated activation or reaction free energies were obtained as averages and standard deviations over 30 independent EVB trajectories, as described in the Supporting Information. The standard error of the mean (s.e.m.) is ≤0.8 kcal·mol^–1 and <0.2 kcal·mol^–1 for the reactions of the pieces, and whole substrate, respectively. The experimental activation free energies, ΔG^‡_exp, were obtained from k_cat using transition state theory.

Activation barriers for the nonenzymatic reaction from refs (10c, 11).

Table 1. Barriers for Nonenzymatic Deprotonation of GAP, and for the TIM-Catalyzed Deprotonation of GAP, GA, and GA·HPi, at 25 °Ca.

Table 1. Barriers for Nonenzymatic Deprotonation of GAP, and for the TIM-Catalyzed Deprotonation of GAP, GA, and GA·HP_i, at 25 °C^a.