You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Characteristics of Nearly Dry Enzymes in Organic Solvents: Implications for Biocatalysis in the Absence of Water
Douglas S. Clark
Philosophical Transactions: Biological Sciences
Vol. 359, No. 1448, The Molecular Basis of Life: Is Life Possible without Water? (Aug. 29, 2004), pp. 1299-1307
Published by: Royal Society
Stable URL: http://www.jstor.org/stable/4142229
Page Count: 9
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
We have examined enzymes in nearly anhydrous organic solvents spanning a wide range of dielectric constants using a combination of electron paramagnetic resonance (EPR) spectroscopy, molecular dynamics simulations., high-pressure kinetic studies and the electrostatic model of Kirkwood. This approach enabled us to investigate the relationship between catalytic activity, protein flexibility and solvent polarity for an enzymatic reaction proceeding through a highly polar transition state in the near absence of water. Further insights into water-protein interactions and the involvement of water in enzyme structure and function have been obtained by EPR and multinuclear nuclear magnetic resonance studies of enzymes suspended and immobilized in organic solvents with and without added water. In these systems, correlations were observed between the water content and enzyme activity, flexibility, and active-site polarity, although the structural properties of suspended and immobilized enzymes differed markedly. These results have helped to elucidate the role of water in molecular events at the enzymic active site leading to improved biocatalysis in low-water environments.
Philosophical Transactions: Biological Sciences © 2004 Royal Society