EARLY INCORPORATION OF CELL-DERIVED CHOLESTEROL INTO PRE-BETA-MIGRATING HIGH-DENSITY LIPOPROTEIN
EARLY INCORPORATION OF CELL-DERIVED CHOLESTEROL INTO PRE-BETA-MIGRATING HIGH-DENSITY LIPOPROTEIN
复制标题
DOI：
10.1021/bi00401a005
复制
发表时间：
1988-01-12
期刊：
影响因子：
2.9
通讯作者：
FIELDING, CJ
中科院分区：
文献类型：
--
作者：
CASTRO, GR;FIELDING, CJ
用[3 H]胆固醇将人皮肤成纤维细胞培养物标记为高胆固醇比活性，并与正常人血浆短暂孵育（1-3分钟）。血浆通过双向琼脂糖-聚丙烯酰胺凝胶电泳分离，并确定血浆脂蛋白中胆固醇标记的早期出现。在1分钟温育时，标记的主要部分处于预β-迁移性载脂蛋白A-I脂蛋白组分，分子量约为70,000.相对于其载脂蛋白A-I含量（总载脂蛋白A-I的1-2%），标记物在该馏分中富集约30倍。这种脂蛋白中标记物的比例与其血浆浓度密切相关。在未标记的细胞存在下进一步温育（2分钟）证明标记物从该级分转移到更高分子量的前-β。apo A-I种类、低密度脂蛋白和α-迁移性apoA-I，占血浆中总apoA-I的大部分（96%）。数据表明，细胞来源的胆固醇的显著部分特异性地转移至前-β-胆固醇。作为血浆中胆固醇转运转移序列的一部分的迁移性脂蛋白a-I种类。
Cultures of human skin fibroblasts were labeled to high cholesterol specific activity with [3H]cholesterol and incubated briefly (1-3 min) with normal human plasma. The plasma was fractionated by two-dimensional agarose-polyacrylamide gel electrophoresis and the early appearance of cholesterol label among plasma lipoproteins determined. A major part of the label at 1-min incubation was in a pre-.beta.-migrating apo A-I lipoprotein fraction with a molecular weight of ca. 70,000. Label was enriched about 30-fold in this fraction relative to its content of apo A-I (1-2% of total apo A-I). The proportion of label in this lipoprotein was strongly correlated with its concentration in plasma. Further incubation (2 min) in the presence of unlabeled cells demonstrated transfer of label from this fraction to a higher molecular weight pre-.beta. apo A-I species, to low-density lipoprotein, and to the .alpha.-migrating apoA-I that made up the bulk (96%) of total apo A-I in plasma. The data suggest that a significant part of cell-derived cholesterol is transferred specifically to a pre-.beta.-migrating lipoprotein a-I species as part of a cholesterol transport transfer sequence in plasma.