Figure 2.

Stabilization of the activation free energy for various amino acid substrates by AV5A-7, relative to the wild-type AspAT. ΔΔG_T^‡ = RTln{(k_cat/K_m)_AV5A-7/(k_cat/K_m)_WT}. Substrate amino acids are shown by three-letter abbreviations. Positive bars indicate that the catalytic efficiency of AV5A-7 is higher than that of the wild-type AspAT, and negative bars indicate vice versa. Exact values could not be determined for valine and isoleucine; therefore, ΔΔG_T^‡ values for their 2-oxo acids are shown for these amino acids (asterisks).