EFFECTS OF THE DIELECTRIC CONSTANT 



811 



Table 15-2 



Effects of Organic Substances on the Hydrolysis of Methyl Hippurate 



BY o-Chymotrypsin " 



" From Applewhite et al. (1958). 



component in the interaction with the enzyme and a greater affinity between 

 the enzyme and the substrate at lower vakies of the dielectric constant. 

 This has indeed been found by Laidler and Ethier (1953) to be the case. 

 The Michaelis constant decreases progressively as the methanol concen- 

 tration is raised to 30% (Table 15-3). Simultaneously the rate constant, 

 ^2, for the breakdown of the ES complex is slightly increased. The over-all 

 enzyme rate in mixtures of water and dioxane increases as the dioxane con- 



Table 15-3 

 Effects of Methanol on the Kinetic Constants of Myosin ATPase "■ 



'^ From Laidler and Ethier (1953). The dielectric constants were taken from Harned 

 and Owen (1958) and are significantly lower than the values used by Laidler and Ethier. 



