Wright J R, Benson B J, Williams M C, Goerke J, Clements J A
Biochim Biophys Acta. 1984 Dec 21;791(3):320-32. doi: 10.1016/0167-4838(84)90343-1.
The goal of this investigation was to characterize the proteins in subfractions of alveolar surfactant obtained by lung lavage and separated by differential centrifugation. It was previously demonstrated that the material in the more sedimentable fraction, which was enriched in tubular-myelin and was surface-active may be a precursor to the less sedimentable, vesicular, inactive material [1]. Separation of the proteins by polyacrylamide gel electrophoresis showed that the more sedimentable subfractions and rabbit surfactant isolated by conventional methods contained proteins with molecular weights comparable to those previously reported for alveolar surface active material (approximately 36 000 and 10 000). The less sedimentable subfractions contained less of these proteins. Immunoblots with anti-dog surfactant apoprotein antibodies, which cross-react with rabbit proteins, supported these observations. Immunoblots also showed that all of the subfractions contained serum proteins and secretory IgA, with the less sedimentable subfractions containing more secretory IgA. These results suggested that changes in protein composition may accompany functional changes in surfactant in the alveoli.
本研究的目的是对通过肺灌洗获得并经差速离心分离的肺泡表面活性物质亚组分中的蛋白质进行表征。先前已证明，沉降性较强的组分中富含管状髓磷脂且具有表面活性的物质可能是沉降性较弱的囊泡状无活性物质的前体[1]。通过聚丙烯酰胺凝胶电泳对蛋白质进行分离显示，沉降性较强的亚组分以及通过传统方法分离的兔表面活性物质中所含蛋白质的分子量与先前报道的肺泡表面活性物质的分子量相当（约36000和10000）。沉降性较弱的亚组分中这些蛋白质的含量较少。与兔蛋白发生交叉反应的抗犬表面活性物质载脂蛋白抗体的免疫印迹证实了这些观察结果。免疫印迹还显示，所有亚组分均含有血清蛋白和分泌型IgA，沉降性较弱的亚组分中分泌型IgA含量更高。这些结果表明，蛋白质组成的变化可能伴随肺泡表面活性物质功能的变化。
