Synthesis of optically pure S-sulfoxide by Escherichia coli transformant cells coexpressing the P450 monooxygenase and glucose dehydrogenase genes

J Ind Microbiol Biotechnol. 2011 May;38(5):633-41. doi: 10.1007/s10295-010-0809-3. Epub 2010 Aug 19.

Abstract

A cytochrome P450 monooxygenase (P450SMO) from Rhodococcus sp. can catalyze asymmetric oxygenation of sulfides to S-sulfoxides. However, P450SMO-catalyzed biotransformations require a constant supply of NAD(P)H, the expense of which constitutes a great hindrance for this enzyme application. In this study, we investigated the asymmetric oxygenation of sulfide to S-sulfoxide using E. coli cells, which co-express both the P450SMO gene from Rhodococcus sp. and the glucose dehydrogenase (GDH) gene from Bacillus subtilis, as a catalyst. The results showed that the catalytic performance of co-expression systems was markedly improved compared to the system lacking GDH. When using recombinant E. coli BL21 (pET28a-P450-GDH) whole cell as a biocatalyst, NADPH was efficiently regenerated when glucose was supplemented in the reaction system. A total conversion of 100% was achieved within 12 h with 2 mM p-chlorothioanisole substrate, affording 317.3 mg/L S-sulfoxide obtained. When the initial sulfide concentration was increased to 5 mM, the substrate conversion was also increased nearly fivefold: S-sulfoxide amounted to 2.5 mM (396.6 mg/L) and the ee value of sulfoxide product exceeded 98%. In this system, the effects of glucose concentration and substrate concentration were further investigated for efficient biotransformation. This system is highly advantageous for the synthesis of optically pure S-sulfoxide.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillus subtilis / genetics
  • Biotransformation
  • Catalysis
  • Cytochrome P-450 Enzyme System / genetics
  • Cytochrome P-450 Enzyme System / metabolism*
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Glucose 1-Dehydrogenase / genetics
  • Glucose 1-Dehydrogenase / metabolism*
  • NADP / metabolism
  • Rhodococcus / genetics
  • Stereoisomerism
  • Sulfides / metabolism
  • Sulfoxides / chemistry
  • Sulfoxides / metabolism*
  • Transformation, Bacterial

Substances

  • Sulfides
  • Sulfoxides
  • NADP
  • Cytochrome P-450 Enzyme System
  • Glucose 1-Dehydrogenase