Diacylglycerol acyltransferase in maturing sunflower seeds.
نویسندگان
چکیده
Developing sunflower seeds exhibit a high diacylglycerol acyltransferase (DAGAT, EC 2.3.1.20) activity. The distribution of the enzyme has been studied in subcellular fractions prepared by differential centrifugation of seed homogenate. Its activity was characterized using [1-(14)C]oleoyl-CoA and diolein dispersed in Tween 20. Some properties of the microsomal fraction of DAGAT were investigated. Hyperbolic kinetics were observed, the apparent K(m) was 60 microM and the specific activity of the reaction 15 pmol/min/mg of protein. Addition of BSA (0.1%) stimulated oleate incorporation, which was not dependent on the presence of exogenous diacylglycerol. Detergents which might solubilize DAGAT, Triton X-100 and CHAPS, were tested for enzyme inhibition, and CHAPS was found to be the least denaturing.
منابع مشابه
Cloning and characterization of a cDNA encoding type 1 diacylglycerol acyltransferase from sunflower (Helianthus annuus L.).
A full-length cDNA encoding a putative diacylglycerol acyltransferase (DGAT; EC 2.3.1.20) was obtained from sunflower (Helianthus annuus L.) seeds. The 1524-bp open reading frame of this cDNA, designated as HaDGAT1, encodes a protein of 507 amino acids with a molecular mass of 58.5 kDa showing high homology to DGAT1 enzymes of other plants. The protein characters, such as a predicted structure ...
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A selection o f lipids from achenes, cotyledons after germination, roots and leaves o f normal and high oleic varieties o f sunflower were analyzed with regard to their fatty acid profiles. The lipids included triacylglycerol and phosphatidylcholine as ER-made components and monoand digalactosyl diacylglycerol as plastid-localized glycolipids. A comparison o f fatty acid pat terns showed that ...
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ورودعنوان ژورنال:
- Biochemical Society transactions
دوره 28 6 شماره
صفحات -
تاریخ انتشار 2000