Acyltransferase diacylglycerol

FIGURE 25.20 Triacylglycerols are formed primarily by the action of acyltransferases on mono- and diacylglycerol. Acyltransferase in E. coli is an integral membrane protein (83 kD) and can utilize either fatty acyl-CoAs or acylated acyl carrier proteins as substrates. It shows a particular preference for palmitoyl groups. Eukaryotic acyltransferases nse only fatty acyl-CoA molecnles as substrates. 

H. S. and Kim, Y. K. 2002. Quinolone alkaloids, diacylglycerol acyltransferase inhibitors from the fruits of Evodia rutaecarpa. Planta Medica, 68 1131-1133. 

Mectianism of Action A combination of ethyl esters of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) that inhibits acyl coenzyme A l,2-diacylglycerol acyltransferase and increases peroxisomal oxidation in the liver. Therapeutic Effect Reduces the synthesis of triglycerides in the liver. 

N Mayorek, J Bar-Tana. Inhibition of diacylglycerol acyltransferase by 2-bromo-octanoate in cultured rat hepatocytes. J Biol Chem 260 6528-6532, 1985. 

H Tomoda, M Ito, N Tabata, R Masuma, Y Yamaguchi, S Omura. Amidepsines, inhibitors of diacylglycerol acyltransferase produced by Humicola sp. FO-2942.1. Production, isolation and biological properties. J Antibiot 48 937-941, 1995. 

N Tabata, M Ito, H Tomoda, S Omura. Xanthohumols, diacylglycerol acyltransferase inhibitors, from Humulus lupulus. Phytochemistry 46 683-687, 1997. 

El Tomoda, Y Ohyama, A Abe, N Tabata, M Namikoshi, Y Yamaguchi, R Masuma, S Omura. Roselipins, inhibitors of diacylglycerol acyltransferase, produced by Gliocladium roseum KF-1040. J Antibiot 52 689-694, 1999. 

S Cases, S J Smith, Y-W Zheng, HM Myers, SR Lear, E Sande, S Novak, C Collins, CB Welch, AJ Lusis, SK Erickson, RV Farese Jr. Identification of a gene encoding an acyl CoA diacylglycerol acyltransferase, a key enzyme in triacylglycerol synthesis. Proc Natl Acad Sci (USA) 95 13018-13023, 1998. 

Marshall, M.O., Knudsen, J. 1980. Factors influencing the in vitro activity of diacylglycerol acyltransferase from bovine mammary gland and liver towards butyryl-CoA and palmi-toyl-CoA. Biochim. Biophys. Acta 617, 393-397. 

Winter, A., Kramer, W., Werner, F.A.O., Rollers, S., Kata, S., Durstewitz, G., Buitkamp, J., Womack, J.E., Thaller, G., Fries, R. 2002. Association of a lysine-232/alanine polymorphism in a bovine gene encoding acyl-CoA diacylglycerol acyltransferase (DGAT1) with variation at a quantitative trait locus for milk fat content. Proc. Nat. Acad. Sci. (USA)... 

Dahlqvist, A., Stahl, U., Lenman, M., Banas, A., Lee, M., Sandager, L., Ronne, H., and Stymne, S. 2000. Phospholipid diacylglycerol acyltransferase An enzyme that catalyzes the acyl-CoA-independent formation of triacylglycerol In yeast and plants. Proc. Natl. Acad. Sci., 97, 6487-6492. 

Casaschi, A., Wang, Q., Dang, K., Richards, A., Theriault, A. (2002). Intestinal apoUpoprotein B secretion is inhibited by the flavonoid quercetin potential role of microsomal triglyceride transfer protein and diacylglycerol acyltransferase. Lipids, 37, 647-652. 

Fig. 31 Prenylflavonoids with anti-diacylglycerol acyltransferase (DGAT) from the roots of Sophora flavescens, and two flavanones and two flavonols without anti-DGAT...

The final step in TAG synthesis occurs by the action of acyl-GoA diacylglycerol acyltransferase (DGAT) witli DAG and fatty acyl-GoA as substrates (Fig. 11.2). DGAT is assumed to be a microsomal enzyme. The membrane-bound enzyme has been only partially purified from rat liver microsomes [124]. Gases and coworkers [125] have identified a mouse cDNA encoding DGAT and, in addition, an expressed sequence tag clone that shared regions of similarity with acyl-GoA cholesterol acyltransferase, an enzyme that also uses fatty acyl-CoA as a sub-... 

M.A. Polokoff and R.M. Bell, Solubilization, partial purification and characterization of rat liver microsomal diacylglycerol acyltransferase, Biochim. Biophys. Acta, 1980, 618, 129-142. 

Palacpac, N. M., Hiramine, Y., Seto, S., Hiramatsu, R., Horii, T., and Mitamura, T. (2004). Evidence that Plasmodium falciparum diacylglycerol acyltransferase is essential for intraer-ythrocytic proliferation. Biochem. Biophys. Res. Commun. 321,1062-1068. 

Fig. 5. Pathway depicting how flux through phosphatidylcholine (product of reaction 3) can promote acyl group diversity in plant triacylglycerols. Production of 18 2 (boxed) at the sn-2 position and its transfer to TG is used as a sample modification. Other fatty acid alterations may be substituted. Enzymes 1, glycerol-3-phosphate acyl-CoA acyltransferase and lysophosphatidic acid acyl-CoA acyltransferase 2, phosphatidic acid phosphatase 3, diacylglyceroliCDP-aminoalcohol aminoalcoholphosphotransferase 4, 18 l-desaturase or other fatty acid modifying enzyme 5, phosphlipid diacylglycerol acyltransferase 6, diacylglycerol acyltransferase 7, acyl-CoA phosphatidylcholine acyltransferase or phospholipase plus acyl-CoA synthetase.

ASH Diacylglycerol acyltransferase 50% reduction in seed TAG Slow germination... 

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