as key distances at each stationary point. From this data, it can be seen that all chimeras are less active than the parent enzymes, although, similarly to our prior work, the changes in the calculated values are not large enough to account for the larger observed changes in kcat (Table ), further indicating the putative importance of dynamical effects, as in our study of the two parent enzymes. In particular, of the residues identified from our EVB simulations as having larger differences in their electrostatic contributions to catalysis (Figure ), R112, E115, K116 and K120 are all residues found on the E-loop. As in our prior computational work, the calculated transition states for each system are very similar; however, as can be seen from Figure , there are in particular differences in the electrostatic contributions from the side chains of K120 and F182/Q182, as well as the side chain of E115. kcal mol -1 ) side chain contributions to TS stabilization can be found in Table .