Intrinsic effects of solvent polarity on enzymic activation energies
β Scribed by Jungbae Kim; Douglas S. Clark; Jonathan S. Dordick
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 85 KB
- Volume
- 67
- Category
- Article
- ISSN
- 0006-3592
No coin nor oath required. For personal study only.
β¦ Synopsis
The effect of organic solvents on subtilisin Carlsberg catalysis has been investigated with the aid of a thermodynamic analysis. Saturation solubility experiments were performed to provide a quantitative measure of substrate desolvation from the reaction medium. This enabled calculation of the intrinsic enzymic activation energy and resulted in a linear free energy relationship with respect to solvent polarity. The results indicate that the intrinsic activation energy of subtilisin catalysis is lowest in polar organic solvents, which may be due to transition state stabilization of the enzyme's polar transition state for transesterification.
π SIMILAR VOLUMES
Addition of water to cereal grains and food products such as flour, bread and crackers stimulates ultraweak chemiluminescence, the intensity of which depends upon cereal species, its origin and history, grinding, time after grinding, initial moisture content, solvent, temperature and additives. Pure
There have been many investigations on the effect of solvents on the dynamic moduli of concentrated polymer solutions. However, most of the polymers investigated were nonpolar, such as polystyrenes and polybutadienes. Moreover, the samples were usually model polymers of very narrow molecular weight
Catalytic activities of β£-chymotrypsin and subtilisin Carlsberg in various hydrous organic solvents were measured as a function of how the enzyme suspension had been prepared. In one method, lyophilized enzyme was directly suspended in the solvent containing 1% water. In another, the enzyme was prec