APOLIPOPROTEIN-J IS ASSOCIATED WITH PARAOXONASE IN HUMAN PLASMA
APOLIPOPROTEIN-J IS ASSOCIATED WITH PARAOXONASE IN HUMAN PLASMA
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DOI：
10.1021/bi00169a026
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发表时间：
1994-01-25
期刊：
影响因子：
2.9
通讯作者：
HARMONY, JAK
中科院分区：
文献类型：
--
作者：
KELSO, GJ;STUART, WD;HARMONY, JAK
载脂蛋白J（apoJ）的高密度脂蛋白（HDL），从人血浆中分离的免疫亲和层析，与apoAI和一种蛋白质约44 kDa。为了推进我们的理解apoJ在血管系统中的作用，进行了全面的调查，以确定和表征这44 kDa的蛋白质，并研究其与apoJ的相互作用。44 kDa的蛋白质，单体糖基化的多肽，被确定为血清对氧磷酶的N-末端测序。对氧磷酶以两种氧化态存在：一种含有所有游离半胱氨酸，而另一种在Cys 42和Cys 284之间具有一个二硫键。对八种人体组织的北方分析显示对氧磷酶信息仅存在于肝脏中。大多数apoJ/对氧磷酶-HDL为90-140 kDa;然而，并非所有血浆对氧磷酶都与apoJ相关。特异性的载脂蛋白J/对氧磷酶的相互作用，推断亲和纯化的载脂蛋白J-HDL中的两种蛋白质的恒定摩尔比，证实了在直接结合试验。对于纯化的蛋白质，当对氧磷酶包被浓度从0.5 μ g/mL增加到2.0 μ g/mL时，apoJ对固定化对氧磷酶的表观亲和力增加超过5倍。对氧磷酶的两种氧化态以相等的亲和力与apoJ结合。我们的数据结合其他证据表明，血浆中apoJ与对氧磷酶的联系可能是血管损伤的预测因子。
Apolipoprotein J (apoJ)-containing high-density lipoproteins (HDL), isolated from human plasma by immunoaffinity chromatography, are associated with apoAI and a protein of approximately 44 kDa. In order to advance our understanding of apoJ's role in the vasculature, a comprehensive investigation was performed to identify and characterize this 44-kDa protein and to study its interaction with apoJ. The 44-kDa protein, a monomeric glycoyslated polypeptide, was identified by N-terminal sequencing as serum paraoxonase. Paraoxonase exists in two oxidation states: one contains all free cysteines while the other has one disulfide bond between Cys42 and Cys284. Northern analysis of eight human tissues shows paraoxonase message present only in the liver. The majority of apoJ/paraoxonase-HDL are 90-140 kDa; however, not all of the plasma paraoxonase is associated with apoJ. The specificity-of the apoJ/paraoxonase interaction, inferred by the constant mole ratio of the two proteins in affinity-purified apoJ-HDL, is confirmed in direct binding assays. For purified proteins, there is more than a 5-fold increase in the apparent affinity of apoJ for immobilized paraoxonase as the paraoxonase coating concentration is increased from 0.5 to 2.0 mug/mL. Both oxidation states of paraoxonase bind to apoJ with equal affinity. Our data combined with other evidence suggest that the plasma link of apoJ with paraoxonase will be implicated as a predictor of vascular damage.