| Comments |
"While a full consideration of the effects of the reaction characteristics on its kinetics is beyond the scope of this review, [investigators] note that different EC classes are characterized by significantly different distributions of kcat values (Figure S5 of the Supporting Information). For example, isomerases (EC 5.X.X.X) exhibit a median kcat of 33.5 s^-1, an order of magnitude higher than that of ligases (EC 6.X.X.X), with a median kcat of 3.7 s^1. It is possible that the different mechanisms and activation energy barriers of different reaction classes may correlate with the catalyzed rates, but at present, the available data do not allow a systematic exploration of these mechanistic issues." |