Chymotrypsin limiting factor

A.24.1 kcatIKM. Chymotrypsin = 2 x 10" Carbonic anhydrase = 7.5 x 10 Catalase = 3.89 x 10 Penicillinase = 4 x 10 Lysozyme = 8.33 X 10". Diffusion is the most likely limiting factor for Cai bonic anhydrase, Catalase, and Penicillinase because their KciaIKm is on the order of 10 Chymotrypsin and lysozyme are most likely limited by something other than diffusion. 

Figure 17.19 Rates of hydrolysis of two families of esters by a hydrolase, chymotrypsin. The esters of N-acetyl-L-phenylalanine exhibit very similar rates because the process in each case is limited by the same enzyme deacylation reaction (Zerner et al., 1964). The esters of N-benzoyl glycine exhibit rates varying by more than a factor of 3 because their hydrolyses are mostly limited by the initial enzyme acylation step (Epand and Wilson, 1963).

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