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标题：Evidence for altered positional specificity of LCAT in vivo studies with docosahexaenoic acid feeding in humans
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作者：Papasani V. Subbaiah ; Jennifer M. Sowa ; Michael H. Davidson 等
期刊名称：JLR Papers In Press
印刷版ISSN：0022-2275
电子版ISSN：1539-7262
出版年度：2004
卷号：45
期号：12
页码：2245-2251
DOI：10.1194/jlr.M400197-JLR200
语种：English
出版社：American Society for Biochemistry and Molecular Biology
摘要：The percentage of saturated cholesteryl esters (CEs) synthesized by human LCAT is several times higher than expected from the sn -2 acyl composition of plasma phosphatidylcholine (PC), whereas the synthesis of 20:4 CE and 22:6 CE is much lower than expected. To explain these discrepancies, we proposed that LCAT transfers some saturated fatty acids from the sn -1 position of PC species that contain 20:4 or 22:6 at sn -2. The present studies provide in vivo evidence for this hypothesis. We determined the composition and synthesis of CE species in plasma of volunteers before and after a 6 week dietary supplementation with docosahexaenoic acid (22:6; DHA). In addition to an increase in the DHA content of all plasma lipids, there was a significant (+12%; P sn -2 of PC. The increase of DHA in CE was much lower than its increase at sn -2 of PC. Ex vivo synthesis of CE species in plasma showed a significant (+24%; P sn -2 of PC. These results show that the positional specificity of human LCAT is altered when the concentration of 16:0-22:6 PC is increased by DHA supplementation.