Deeg M A
Department of Medicine, University of Washington, Seattle 98195.
Braz J Med Biol Res. 1994 Feb;27(2):375-81.
Glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) has recently been shown to be associated with high-density lipoproteins (HDL) in bovine serum. To determine the distribution of GPI-PLD among lipoproteins and characterize the GPI-PLD-containing lipoproteins in human plasma, we used dextran sulfate and immunoaffinity chromatography to isolate apolipoprotein-specific lipoproteins. This procedure allowed fractionation of lipoprotein particles into those containing apolipoprotein B (Lp B), apolipoproteins AI and AII (Lp AI/AII), or apolipoprotein AI only (Lp AI). In five plasma samples with HDL cholesterol ranging from 40 to 129 mg/dl, 75 +/- 12% (mean +/- SD) of the GPI-PLD activity was associated with Lp AI, 11 +/- 13% with Lp AI/AII, while only 13 +/- 9% was present in plasma devoid of these lipoproteins, suggesting that most of the GPI-PLD in human plasma is associated with apolipoprotein AI. No GPI-PLD activity was detected in Lp B. Further characterization of the GPI-PLD-containing lipoproteins by gel filtration chromatography, nondenaturing poly-acrylamide and agarose gel electrophoresis revealed that GPI-PLD was restricted to an apolipoprotein AI-containing particle or complex that was small (apparent mean Mw of 140 kDa) and distinct from the bulk of HDL. Thus, the majority of plasma GPI-PLD appears to be specifically associated with a small, minor fraction of apolipoprotein AI.
糖基磷脂酰肌醇特异性磷脂酶D（GPI-PLD）最近被证明与牛血清中的高密度脂蛋白（HDL）有关。为了确定GPI-PLD在脂蛋白中的分布并表征人血浆中含GPI-PLD的脂蛋白，我们使用硫酸葡聚糖和免疫亲和色谱法分离载脂蛋白特异性脂蛋白。该方法可将脂蛋白颗粒分离为含载脂蛋白B的颗粒（Lp B）、含载脂蛋白AI和AII的颗粒（Lp AI/AII）或仅含载脂蛋白AI的颗粒（Lp AI）。在五份HDL胆固醇含量在40至129 mg/dl之间的血浆样本中，75±12%（平均值±标准差）的GPI-PLD活性与Lp AI相关，11±13%与Lp AI/AII相关，而在不含这些脂蛋白的血浆中仅存在13±9%，这表明人血浆中大部分GPI-PLD与载脂蛋白AI相关。在Lp B中未检测到GPI-PLD活性。通过凝胶过滤色谱、非变性聚丙烯酰胺和琼脂糖凝胶电泳对含GPI-PLD的脂蛋白进行进一步表征，结果显示GPI-PLD局限于一种含载脂蛋白AI的颗粒或复合物，该颗粒较小（表观平均分子量为140 kDa），且与大部分HDL不同。因此，血浆中的大部分GPI-PLD似乎与一小部分载脂蛋白AI特异性相关。
