Sialic acid moiety of apolipoprotein E and its impact on the formation of lipoprotein particles in human cerebrospinal fluid
Sialic acid moiety of apolipoprotein E and its impact on the formation of lipoprotein particles in human cerebrospinal fluid
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DOI：
10.1016/j.cca.2008.12.018
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发表时间：
2009-04-01
影响因子：
5
通讯作者：
Yamauchi, Kazuyoshi
中科院分区：
文献类型：
--
作者：
Kawasaki, Kenji;Ogiwara, Naoko;Yamauchi, Kazuyoshi
背景资料：脑脊液中的载脂蛋白E（apo E）富含唾液酸（SA），某些蛋白质的唾液酸化可调节其生物学功能。本研究的目的是定量CSF apoE中SA的含量，并对CSF中含有apoE的脂蛋白进行更详细的表征。方法：测定CSF apoE中SA的方法是基于SA转化为对氨基苯甲酸乙酯衍生的N-乙酰甘露糖胺，然后进行HPLC分析。CSF SA和血清SA水平分别为25.9 +/- 1.5和2209 +/- 196 μ mol/l：然而，当SA值通过总蛋白浓度校正时，CSF SA值约为血清中SA值的3.5倍。CSF含apoE脂蛋白组分中的SA水平为总CSF SA的5.3 +/- 1.3%，并且与CSF apoE浓度相关。然而，SA与apoE的比值与CSF脂质浓度成反比。结论：脑脊液apoE分子中的SA部分可能影响含apoE的脂蛋白颗粒的形成和脂蛋白在中枢神经系统的转运。(C)2008 Elsevier B. V.保留所有权利。
Background: Apolipoprotein (apo) E in the cerebrospinal fluid (CSF) is abundant with sialic acid (SA), and sialylation of certain proteins is known to modulate biological function. The aim of the present study was to quantify the SA content in CSF apoE and carry out the more detailed characterization of the CSF apoE-containing lipoproteins.Methods: The method for the determination of the SA in CSF apoE was based on the conversion of SA into p-aminobenzoic acid ethyl ester-derivatized N-acetylmannosamine, followed by HPLC analysis.Results: The levels of CSF SA and serum SA were 25.9 +/- 1.5 and 2209 +/- 196 mu mol/l, respectively: however, when the SA values were corrected by the total protein concentrations, CSF SA values were approximately 3.5-fold of those in the serum. The SA levels in the CSF apoE-containing lipoprotein fractions were 5.3 +/- 1.3% of total CSF SA, and were correlated with the CSF apoE concentrations. However, the ratios of SA to apoE were inversely proportional to the CSF lipid concentrations. The lipoprotein particle sizes were larger when the ratios of SA to CSF apoE were greater.Conclusion: The SA moiety of the CSF apoE molecules may affect the formation of the apoE-containing lipoprotein particles and the regulation of lipid delivery in CNS. (C) 2008 Elsevier B.V. All rights reserved.