Gries A, Nimpf J, Nimpf M, Wurm H, Kostner G M
Clin Chim Acta. 1987 Apr 15;164(1):93-100. doi: 10.1016/0009-8981(87)90110-0.
The distribution of Lpa-specific protein (Apo A) among various fractions of human serum was investigated. The following results were obtained. In very low density lipoproteins (VLDL) of fasting human serum Apo A cannot be detected. Most of Apo A is complexed to LDL forming lipoprotein a (Lpa) present in the density fraction of 1.006-1.125 g/ml. Only approximately 5% of Apo A are found in the d greater than 1.125 bottom fraction after ultracentrifugation. Phosphotungstate-Mg (PTA), heparin-Mn (Hep) and dextran sulfate-Mg (DS) precipitate approximately 95% of serum Lpa together with the Apo B containing lipoproteins. Also monospecific antibodies against Apo B do not precipitate all Lpa and leave approximately 3% of Apo A in the supernatant. With polyethylene glycol (PEG) on the other hand, virtually all Lpa is removed since this reagent also precipitates Lpa and Apo A. Apo A of the bottom fraction after ultracentrifugation and of the supernatant after selective precipitation is not stainable with Sudan black and probably represents a protein which is not associated with lipids.
研究了人血清不同组分中Lpa特异性蛋白（载脂蛋白A）的分布情况。得到了以下结果。在空腹人血清的极低密度脂蛋白（VLDL）中无法检测到载脂蛋白A。大部分载脂蛋白A与低密度脂蛋白结合形成脂蛋白a（Lpa），存在于密度为1.006 - 1.125 g/ml的组分中。超速离心后，仅约5%的载脂蛋白A存在于密度大于1.125的底部组分中。磷钨酸镁（PTA）、肝素锰（Hep）和硫酸葡聚糖镁（DS）会沉淀约95%的血清Lpa以及含载脂蛋白B的脂蛋白。同样，抗载脂蛋白B的单特异性抗体也不能沉淀所有Lpa，上清液中会残留约3%的载脂蛋白A。另一方面，聚乙二醇（PEG）几乎能去除所有Lpa，因为该试剂也会沉淀Lpa和载脂蛋白A。超速离心后底部组分以及选择性沉淀后上清液中的载脂蛋白A不能被苏丹黑染色，可能代表一种不与脂质相关的蛋白质。
