Abstract
Alpha-lipoic acid (LA) is an important enzyme cofactor widely used by organisms and is also a natural antioxidant for the treatment of pathologies driven by low levels of endogenous antioxidants. In order to establish a safer and more efficient process for LA production, we developed a new biological method for LA synthesis based on the emerging knowledge of lipoic acid biosynthesis. We first cloned the lipD gene, which encodes the lipoyl domain of the E2 subunit of pyruvate dehydrogenase, allowing high levels of LipD production. Plasmids containing genes for the biosynthesis of LA were subsequently constructed utilizing various vectors and promotors to produce high levels of LA. These plasmids were transformed into the Escherichia coli strain BL21. Octanoic acid (OA) was used as the substrate for LA synthesis. One transformant, YS61, which carried lipD, lplA, and lipA, produced LA at levels over 200-fold greater than the wild-type strain, showing that LA could be produced efficiently in E. coli using genetic engineering methods.
Highlights
lipoic acid (LA) is a sulfur-containing cofactor found in most prokaryotic and eukaryotic organisms
Comparing production of the lipoyl domain from different plasmids Since LA biosynthesis is closely linked with apo-lipoyl domain, this domain should be expressed at high levels in order to achieve large-scale production of LA
Low yield of the octanoylated-lipoyl domain and holo-lipoyl domain was obtained in YS17 even when Octanoic acid (OA) or LA was added (Fig 3)
Summary
LA is a sulfur-containing cofactor found in most prokaryotic and eukaryotic organisms. It exists in water soluble oxidized and reduced forms [1]. LA is essential for the function of several key enzymes involved in oxidative and single carbon metabolism including pyruvate dehydrogenase (PDH), 2-oxoglutarate dehydrogenase (2-OGDH), branched-chain 2-oxo-acid dehydrogenase, acetoin dehydrogenase and the glycine cleavage system [8, 9]. A specific subunit is modified by covalent attachment of LA to the ε-amino group of specific lysine residues within conserved domains
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
