Median kcat of isomerases & ligases

Range isomerases 33.5s^-1: ligases 3.7s^-1 sec^-1
Organism Unspecified
Reference Bar-Even A. et al., The moderately efficient enzyme: evolutionary and physicochemical trends shaping enzyme parameters. Biochemistry. 2011 May 31 50(21):4402-10. doi: 10.1021/bi2002289. p.4405 left column bottom paragraphPubMed ID21506553
Method "Here [investigators] describe a global view of enzyme parameters with the aim of highlighting the forces that shape the catalytic efficiency of enzymes."
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."
Entered by Uri M
ID 111416