Enantioselective transesterification catalysis by nanosized serine protease subtilisin Carlsberg particles in tetrahydrofuran |
| |
Authors: | Betzaida Castillo Gabriel Barletta |
| |
Institution: | a Department of Chemistry, University of Puerto Rico, Río Piedras Campus, PO Box 23346, San Juan, Puerto Rico 00931-3346 b Department of Chemistry, University of Puerto Rico, College at Humacao, CUH Station, Humacao, Puerto Rico 00791 |
| |
Abstract: | Enzyme catalysis in organic solvents is a powerful tool for stereo-selective synthesis but the enantioselectivity is still hard to predict. To overcome this obstacle, we employed a nanoparticulate formulation of subtilisin Carlsberg (SC) and designed a series of 14 structurally related racemic alcohols. They were employed in the model transesterification reaction with vinyl butyrate and the enantioselectivities were determined. In general, short alcohol side chains led to low enantioselectivties, while larger and bulky side chains caused better discrimination of the enantiomers by the enzyme. With several bulky substrates high enantioselectivities with E>100 were obtained. Computational modeling highlighted that key to high enantioselectivity is the discrimination of the R and S substrates by the sole hydrophobic binding pocket based on their size and bulkiness. While bulky S enantiomer side chains could be accommodated within the binding pocket, bulky R enantiomer side chains could not. However, when also the S enantiomer side chain becomes too large and does not fit into the binding pocket anymore, enantioselectivity accordingly drops. |
| |
Keywords: | Enantioselective catalysis Non-aqueous enzymology Enzyme Secondary alcohol Serine protease |
本文献已被 ScienceDirect 等数据库收录! |
|