Shelley S A, Paciga J E, Lowell N E, Balis J U
Biochim Biophys Acta. 1985 Mar 29;839(1):50-6. doi: 10.1016/0304-4165(85)90180-1.
A comparative study of lung surfactant associated proteins was undertaken to determine which mammalian species would best serve as models for investigating alterations of the human lung surfactant system. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of purified surfactants in the presence of dithiothreitol revealed that surfactant invariably contains at least one peptide with molecular weight of 30 000-40 000. In the absence of disulfide reducing agents, the above peptides were in the form of high-molecular-weight proteins (greater than 400 kDa) in primates and cat, whereas in dog, rat and rabbit, the protein was a 72 kDa dimer. The 30-40 kDa peptide subunits were isolated from human, rat and dog surfactants and found to contain four or five residues of hydroxyproline. Antisera to either the human 34 kDa peptide or high-molecular-weight proteins reacted with the high-molecular-weight bands, the 34 kDa subunit and at least six intermediate disulfide-linked forms separated from purified human surfactant by electrophoresis under nonreducing conditions. Following electrophoresis in the presence of dithiothreitol, both antisera detected the 34 kDa peptide as well as other peptides ranging in molecular weight from 23 000 to 160 000. The isolated 34 kDa peptide readily reaggregated into disulfide-linked forms including 68 and 100 kDa complexes which were not reduced by 40 mM dithiothreitol. We conclude that the 34 kDa surfactant-associated peptide forms a complex system of monomeric and multimeric proteins, which varies among the species and could conceivably vary in distribution during lung development or disease.
进行了一项肺表面活性物质相关蛋白的比较研究，以确定哪种哺乳动物物种最适合作为研究人类肺表面活性物质系统改变的模型。在二硫苏糖醇存在下对纯化的表面活性物质进行十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示，表面活性物质总是含有至少一种分子量为30000-40000的肽。在没有二硫键还原剂的情况下，上述肽在灵长类动物和猫中以高分子量蛋白（大于400 kDa）的形式存在，而在狗、大鼠和兔子中，该蛋白是一种72 kDa的二聚体。从人、大鼠和狗的表面活性物质中分离出30-40 kDa的肽亚基，发现其含有四个或五个羟脯氨酸残基。针对人34 kDa肽或高分子量蛋白的抗血清与高分子量条带、34 kDa亚基以及在非还原条件下通过电泳从纯化的人表面活性物质中分离出的至少六种中间二硫键连接形式发生反应。在二硫苏糖醇存在下进行电泳后，两种抗血清均检测到34 kDa肽以及分子量范围为23000至160000的其他肽。分离出的34 kDa肽很容易重新聚集形成二硫键连接的形式，包括68和100 kDa的复合物，这些复合物不会被40 mM二硫苏糖醇还原。我们得出结论，34 kDa的表面活性物质相关肽形成了一个单体和多聚体蛋白的复杂系统，该系统在不同物种之间存在差异，并且在肺发育或疾病过程中其分布可能会发生变化。
