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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1991-2-7
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pubmed:abstractText |
Embryos of Cuphea lanceolata have more than 80 mol% of decanoic acid ('capric acid') in their triacylglycerols, while this fatty acid is virtually absent in phosphatidylcholine (PtdCho). Seed development was complete 25-27 days after pollination, with rapid triacylglycerol deposition occurring between 9 and 24 days. PtdCho amounts increased until day 15 after pollination. Analysis of embryo lipids showed that the diacylglycerol (DAG) pool consisted of mainly long-chain molecular species, with a very small amount of mixed medium-chain/long-chain glycerols. Almost 100% of the fatty acid at position sn-2 in triacylglycerols (TAG) was decanoic acid. When equimolar mixtures of [14C]decanoic and [14C]oleic acid were fed to whole detached embryos, over half of the radioactivity in the DAG resided in [14C]oleate, whereas [14C]decanoic acid accounted for 93% of the label in the TAG. Microsomal preparations from developing embryos at the mid-stage of TAG accumulation catalysed the acylation of [14C]glycerol 3-phosphate with either decanoyl-CoA or oleoyl-CoA, resulting in the formation of phosphatidic acid (PtdOH), DAG and TAG. Very little [14C]glycerol entered PtdCho. In combined incubations, with an equimolar supply of [14C]oleoyl-CoA and [14C]decanoyl-CoA in the presence of glycerol 3-phosphate, the synthesized PtdCho species consisted to 95% of didecanoic and dioleic species. The didecanoyl-glycerols were very selectively utilized over the dioleoylglycerols in the production of TAG. Substantial amounts of [14C]oleate, but not [14C]decanoate, entered PtdCho. The microsomal preparations of developing embryos were used to assess the acyl specificities of the acyl-CoA:sn-glycerol-3-phosphate acyltransferase (GPAT, EC 2.3.1.15) and the acyl-CoA:sn-1-acyl-glycerol-3-phosphate acyltransferase (LPAAT, EC 2.3.1.51) in Cuphea lanceolata embryos. The efficiency of acyl-CoA utilization by the GPAT was in the order decanoyl = dodecanoyl greater than linoleoyl greater than myristoyl = oleoyl greater than palmitoyl. Decanoyl-CoA was the only acyl donor to be utilized to any extent by the LPAAT when sn-decanoylglycerol 3-phosphate was the acyl acceptor. sn-1-Acylglycerol 3-phosphates with acyl groups shorter than 16 carbon atoms did not serve as acyl acceptors for long-chain (greater than or equal to 16 carbon atoms) acyl-CoA species. On the basis of the results obtained, we propose a schematic model for triacylglycerol assembly and PtdCho synthesis in a tissue specialized in the synthesis of high amounts of medium-chain fatty acids.
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pubmed:commentsCorrections |
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-13671378,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-14173322,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-14299609,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-14455159,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-16665518,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-16667178,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-286305,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-3622518,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-4084230,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-4397675,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-4721605,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-475773,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-6465892,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-6833216,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-710426,
http://linkedlifedata.com/resource/pubmed/commentcorrection/2264835-7288294
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0264-6021
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
15
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pubmed:volume |
272
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
31-8
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pubmed:dateRevised |
2010-9-9
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pubmed:meshHeading |
pubmed-meshheading:2264835-Acyl Coenzyme A,
pubmed-meshheading:2264835-Carbon Radioisotopes,
pubmed-meshheading:2264835-Fatty Acids, Nonesterified,
pubmed-meshheading:2264835-Kinetics,
pubmed-meshheading:2264835-Microsomes,
pubmed-meshheading:2264835-Plants,
pubmed-meshheading:2264835-Seeds,
pubmed-meshheading:2264835-Substrate Specificity,
pubmed-meshheading:2264835-Triglycerides
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pubmed:year |
1990
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pubmed:articleTitle |
Regulation of triacylglycerol biosynthesis in embryos and microsomal preparations from the developing seeds of Cuphea lanceolata.
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pubmed:affiliation |
Department of Plant Physiology, Swedish University of Agricultural Sciences, Uppsala.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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