Platelet-derived growth factor: structure, function, and roles in normal and transformed cells.
Platelet-derived growth factor: structure, function, and roles in normal and transformed cells.
复制标题
血小板衍生生长因子：正常细胞和转化细胞中的结构、功能和作用。
DOI：
10.1016/b978-0-12-152826-3.50012-7
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
Huang,JS
中科院分区：
文献类型：
--
作者：
Deuel,TF;Tong,BD;Huang,JS
从大鼠肺表面活性物质中分离出乙醇/乙醚可溶性脱辅基蛋白，占总回收的表面活性物质相关蛋白的17%，并通过柠檬酸色谱法纯化。在4：1氯仿/甲醇中洗脱的蛋白质占乙醇/乙醚可溶性级分中蛋白质的85%以上，并被称为表面活性剂脱辅基蛋白Et（Apo Et）。通过十二烷基硫酸钠聚丙烯酰胺凝胶电泳，该蛋白质的表观分子量约为10，500。评价了Apo Et对原代培养物中分离的颗粒肺细胞（II型肺泡上皮细胞）摄取脂质体形式合成磷脂的影响。制备脂质体以接近肺泡表面活性剂的磷脂组成，并通过放射性标记的二棕榈酰磷脂酰胆碱部分的累积来测量摄取。与载脂蛋白Et孵育2小时的细胞对脂质体磷脂酰胆碱的摄取比对照增加了61%。大多数细胞相关磷脂摄取对胰蛋白酶处理具有抗性，表明在Apo Et存在下脂质体材料的内化增加。载脂蛋白Et对摄取的影响具有浓度和时间依赖性，与细胞损伤、磷脂酶活性或蛋白质的去污剂性质无关。ApoEt对原代培养7 d的颗粒肺细胞摄取磷脂酰胆碱无明显影响。载脂蛋白Et增强了肺泡巨噬细胞对磷脂的摄取，尽管这些细胞的总摄取量低于颗粒肺细胞。由于Apo Et增加肺泡细胞（颗粒肺细胞和肺泡巨噬细胞）对表面活性剂磷脂的摄取速率，因此该蛋白可能是肺表面活性剂磷脂清除的重要生理调节剂。
Ethanol/ether soluble apoproteins, comprising 17% of the total recovered surfactant-associated proteins, were isolated from rat lung surfactant and purified by silicic acid chromatography. The protein that eluted in 4: 1 chloroform/methanol accounted for greater than 85% of protein in the ethanol/ether soluble fraction and was termed surfactant apoprotein Et (Apo Et). By sodium dodecyl sulfate polyacrylamide gel electrophoresis, this protein had an apparent molecular weight of approximately 10,500. Apo Et was evaluated for its effect on uptake of synthetic phospholipids in liposomal form by isolated granular pneumocytes (Type II alveolar epithelial cells) in primary culture. Liposomes were prepared to approximate the phospholipid composition of the alveolar surfactant, and uptake was measured by the accumulation of the radioactively labeled dipalmitoyl phosphatidyl choline fraction. The uptake of liposomal phosphatidylcholine by cells incubated for 2 h with Apo Et was increased by 61% over control. Most of the cell-associated phospholipid uptake was resistant to treatment with trypsin, suggesting an increased internalization of liposomal material in the presence of Apo Et. The effect of Apo Et on uptake was concentration and time dependent and was not associated with cell damage, phospholipase activity, or detergent properties of the protein. Apo Et had no significant effect on phosphatidylcholine uptake by granular pneumocytes maintained for 7 d in primary culture. Apo Et augmented the uptake of phospholipids by alveolar macrophages although total uptake by these cells was less than that observed with granular pneumocytes. Because Apo Et increases the rate of uptake of surfactant phospholipids by alveolar cells (granular pneumocytes and alveolar macrophages), this protein may represent a physiologically important regulator for clearance of lung surfactant phospholipids.