Bioconversion of eicosapentaenoic acid into 5S,15S - and 5R,15R-dihydroxyeicosapentaenoic acids by double-dioxygenating 15S- and 15R-lipoxygenases.

Abstract

Resolvin E series (Rvs), such as RvE4 (5S,15S-dihydroxyeicosapentaenoic acid) and its stereoselective enantiomer (5R,15R-dihydroxyeicosapentaenoic acid), play an important role in promoting the resolution of inflammation and are derived from eicosapentaenoic acid (EPA) by M2 macrophage in human. However, they have been synthesized using expensive and inefficient chemical methods. Here, we performed efficient quantitative production of RvE4 and its enantiomer from epa using Escherichia coli expressing double-dioxygenating 15S-lipoxygenase (15S-LOX) from Archangium violaceum and double-dioxygenating 15R-LOX from Sorangium cellulosum, respectively, with solvent, polymer, and adsorbent resin. The cell density, substrate concentration, solvent types and concentrations, polymer types and concentrations, and resin concentration were optimized for the enhanced bioconversion of epa into RvE4 and its enantiomer. Under the optimized conditions, A. violaceum 15S-LOX and S. cellulosum 15R-LOX expressed in E. coli converted 6.0 mM epa into 4.3 mM (1.44 g/L) RvE4 and 5.8 mM (1.94 g/L) RvE4 enantiomer in 60 min, with productivities of 4.3 and 5.8 mM/h and molar conversions of 72% and 97%, respectively. To date, these are the highest concentrations, productivities, and conversions of RvE4 and its enantiomer. The concentrations of RvE4 and its enantiomer obtained from the conversion of epa with solvent, polymer, and resin were 2.5- and 3.2-fold higher than those without the additives, respectively.