Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: July 3, 2011
Publication Date: July 31, 2011
Citation: Cao, H. 2011. Bioengineering recombinant diacylglycerol acyltransferases. In: Carpi, A., editor. Progress in molecular and environmental bioengineering-from analysis and modeling to technology applications. Rijeka, Croatia: InTech Open Access Publisher. p. 467-482. Technical Abstract: Diacylglycerol acyltransferases (DGATs) catalyze the last and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. At least 115 DGAT sequences are identified from 69 organisms in the GenBank databases. Only a few papers have been published in the last 28 years on the expression of the recombinant DGAT proteins in a bacterial expression system. None of the full-length DGAT1 or DGAT2 had been expressed in E. coli expression system. The difficulties in DGAT expression and purification are due to the nature of these proteins being integral membrane proteins with more than 40% of the total amino acid residues being hydrophobic. Therefore, progress in characterization of the enzymes has been slow. We recently developed a procedure for full-length DGAT expression in E. coli. Expression plasmids were engineered to express tung DGATs fused to maltose binding protein and poly-histidine. The development of the technique should help to purify full-length DGATs for further studies such as raising high titer antibodies and studying the structure-function relationship. Understanding the roles of DGATs in plant oil biosynthesis will help to create new oilseed crops with value-added properties. The elucidation of the precise roles of DGATs in animal and human fat synthesis and deposition may provide clues for therapeutic intervention in obesity and related diseases.