Characterization of bifunctional l -glutathione synthetases from Actinobacillus pleuropneumoniae and Actinobacillus succinogenes for efficient glutathione biosynthesis

摘要: Glutathione (GSH), an important bioactive substance, is widely applied in pharmaceutical and food industries. In this work, two bifunctional L-glutathione synthetases (GshF) from Actinobacillus pleuropneumoniae (GshFAp) succinogenes (GshFAs) were successfully expressed Escherichia coli BL-21(DE3). Similar to the GshF Streptococcus thermophilus (GshFSt), GshFAp GshFAs can be for high titer GSH production because they are less sensitive end-product inhibition (Ki values 33 43 mM, respectively). The active catalytic forms of dimers, consistent with those GshFPm (GshF Pasteurella multocida) GshFSa agalactiae), but different GshFSt S. thermophilus) which monomer. analysis protein sequences three dimensional structures GshFs suggested that binding sites substrates, L-cysteine, L-glutamate, γ-glutamylcysteine, adenosine-triphosphate, glycine highly conserved only very few differences. With sufficient supply precursors, recombinant strains BL-21(DE3)/pET28a-gshFas BL-21(DE3)/pET28a-gshFap able produce 36.6 34.1 mM GSH, molar yield 0.92 0.85 mol/mol, respectively, based on added L-cysteine. results showed potentially good candidates industrial production.