The utilization of the acyl-CoA and the involvement PDAT and DGAT in the biosynthesis of erucic acid-rich triacylglycerols in Crambe seed oil.
The utilization of the acyl-CoA and the involvement PDAT and DGAT in the biosynthesis of erucic acid-rich triacylglycerols in Crambe seed oil.
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DOI：
10.1007/s11745-014-3886-7
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发表时间：
2014-04
期刊：
影响因子：
1.9
通讯作者：
Banas, Antoni
中科院分区：
文献类型：
--
作者：
Furmanek, Tomasz;Demski, Kamil;Banas, Walentyna;Haslam, Richard;Napier, Jonathan;Stymne, Sten;Banas, Antoni
海棠种子的三酰甘油在sn-1和sn-3位含有95%的超长链(>；18碳)脂肪酸(86%的芥酸；22：1的∆13)。这可能表明，海桑三酰甘油不是由磷脂：二酰甘油酰基转移酶(PDAT)作用形成的，而是酰基辅酶A：二酰甘油酰基转移酶(DGAT)活性的结果。然而，微体膜中PDAT和DGAT活性的测定表明，海桑具有显著的PDAT活性，相当于种子油快速积累期间DGAT活性的10%左右。芥酰辅酶A的DGAT比活力在开花后19天比发育前期增加了一倍，是该时期的首选酰基供体，而16：0-辅酶A和18：1-辅酶A的活性保持不变。这表明在芥酸和油的快速积累开始时，诱导了对芥酰辅酶A具有高度专一性的DGAT亚型的表达。对种子发育不同阶段的酰基辅酶A库组成的分析表明，除干燥阶段外，在种子发育的所有阶段，酰基辅酶A中芥酰基团的百分比都远高于复合脂类。这些结果与已发表的结果一致，表明芥酸积累的速率限制步骤是甘油-3-磷酸途径中的酰基转移酶利用芥酰辅酶A。本文的在线版本(doi：10.1007/s117450143886-7)包含补充材料，授权用户可以使用。
The triacylglycerol of Crambe abyssinica seeds consist of 95 % very long chain (>18 carbon) fatty acids (86 % erucic acid; 22:1∆13) in the sn-1 and sn-3 positions. This would suggest that C. abyssinica triacylglycerols are not formed by the action of the phospholipid:diacylglycerol acyltransferase (PDAT), but are rather the results of acyl-CoA:diacylglycerol acyltransferase (DGAT) activity. However, measurements of PDAT and DGAT activities in microsomal membranes showed that C. abyssinica has significant PDAT activity, corresponding to about 10 % of the DGAT activity during periods of rapid seed oil accumulation. The specific activity of DGAT for erucoyl-CoA had doubled at 19 days after flowering compared to earlier developmental stages, and was, at that stage, the preferred acyl donor, whereas the activities for 16:0-CoA and 18:1-CoA remained constant. This indicates that an expression of an isoform of DGAT with high specificity for erucoyl-CoA is induced at the onset of rapid erucic acid and oil accumulation in the C. abyssinica seeds. Analysis of the composition of the acyl-CoA pool during different stages of seed development showed that the percentage of erucoyl groups in acyl-CoA was much higher than in complex lipids at all stages of seed development except in the desiccation phase. These results are in accordance with published results showing that the rate limiting step in erucic acid accumulation in C. abyssinica oil is the utilization of erucoyl-CoA by the acyltransferases in the glycerol-3-phosphate pathway. The online version of this article (doi:10.1007/s11745-014-3886-7) contains supplementary material, which is available to authorized users.
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影响因子：
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作者：
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