Optimization of the Kinetic Resolution of the dl-Phosphomonoesters of Threonine and Serine by Random Mutagenesis of the Acid Phosphatase from Salmonella enterica
✍ Scribed by Teunie van Herk; Aloysius F. Hartog; Harald J. Ruijssenaars; Richard Kerkman; Hans E. Schoemaker; Ron Wever
- Publisher
- John Wiley and Sons
- Year
- 2007
- Tongue
- English
- Weight
- 125 KB
- Volume
- 349
- Category
- Article
- ISSN
- 1615-4150
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✦ Synopsis
Abstract
Acid phosphatases are enzymes with a broad substrate specificity showing hydrolytic activity towards several different organic phosphate monoesters, such as nucleotides and sugar phosphates. The acid phosphatase from Salmonella enterica ser. typhimurium LT2 (PhoN‐Se) is able to hydrolyze O‐phospho‐dl‐threonine to yield L‐threonine with a very high enantioselectivity (E>200). When O‐phospho‐dl‐serine was hydrolyzed by PhoN‐Se, D‐serine was formed, however, the ee values rapidly dropped to 50 %. Random mutagenesis by error‐prone PCR was performed on the phosphatase in order to increase its enantioselectivity in the formation of D‐serine. Two variants with increased selectivity from a library of 9600 mutants have been found, N151D and V78L showing E values of 18.1 and 4.1, respectively, compared to 3.4 for the wild‐type (WT) enzyme.