ABSTRACT
This chapter deals with the effect of pH, temperature, and pressure on the enzyme activity. It describes how temperature and pressure affect on the enzymatic reaction. The rate of the enzyme-catalyzed reaction increases with increasing temperature. However, at higher temperature, the rate decreases gradually. The decrease of the rate at higher temperature must be due to the heat denaturation of enzyme. Therefore, an optimum temperature is derived from the balance of the increase and decrease of the rate. The high pressure affects on the enzyme activity, and most enzymes are reversibly inactivated over 3 kbar, and irreversibly over 7 kbar. α-Chymotrypsin is the protease that catalyzes the hydrolysis of the peptide bond at the C-terminal side of hydrophobic amino acid residues. The tetrahedral transition state intermediate is assumed to be formed at the step formation of the acylated enzyme: enzyme-substrate to ES'.
