Identification of the rate-limiting step in serine proteinases from the effect of temperature on steady-state kinetics
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A New Screening Method for the Directed Evolution of Thermostable Bacteriolytic Enzymes
Published on: November 7, 2012
1Department of Biochemistry and Biophysics, Texas A & M University, College Station 77843.
Abstract:
The effect of temperature on the steady-state kinetics of porcine pancreatic elastase can be used to determine whether acylation or deacylation is the rate-limiting step in catalysis. If acylation is rate-limiting, kcat and kcat/Km will show the same temperature dependence. If deacylation is rate-limiting, kcat will show a greater temperature dependence than kcat/Km. The temperature dependence of the steady-state kinetic parameters of t-Boc-Ala-Ala-Pro-Ala p-nitroanilide and N-acetyl-Ala-Ala-alpha-Aza-Ala p-nitrophenyl ester have been determined and are consistent with this prediction.
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