Figure 2.

Pre-steady-state kinetic and Taft analysis of a series of acyl-CoAs. The dashed line indicates 1 equiv of enzyme: (A) acetoacetyl-CoA (R = Ac), (B) bromoacetyl-CoA (R = Br), (C) chloroacetyl-CoA (R = Cl), and (D) cyanoacetyl-CoA (R = CN). (E) Taft plot for the acylation step of FlK-catalyzed acyl-CoA hydrolysis. Acylation rate constants (k₂) are derived from nonlinear curve fitting of pre-steady-state kinetic time courses. Values are reported as means ± the standard deviation (n = 3). The linear fit gave a ρ* value of 1.7 ± 0.2 (R² = 0.986).