NUCLEOTIDE AND AMINO-ACID-SEQUENCES OF PULMONARY SURFACTANT PROTEIN SP-18 AND EVIDENCE FOR COOPERATION BETWEEN SP-18 AND SP 28-36 IN SURFACTANT LIPID ADSORPTION
NUCLEOTIDE AND AMINO-ACID-SEQUENCES OF PULMONARY SURFACTANT PROTEIN SP-18 AND EVIDENCE FOR COOPERATION BETWEEN SP-18 AND SP 28-36 IN SURFACTANT LIPID ADSORPTION
复制标题
DOI：
10.1073/pnas.84.1.66
复制
发表时间：
1987-01-01
影响因子：
11.1
通讯作者：
WHITE, RT
中科院分区：
文献类型：
--
作者：
HAWGOOD, S;BENSON, BJ;WHITE, RT
肺表面活性剂是一种富含脂质的物质，通过降低周围空气空间中气液界面的表面张力来促进肺泡稳定性。肺泡腔中表面活性剂磷脂的周转速度很快，多项证据表明，在正常呼吸过程中，磷脂表面膜会快速形成和补充。特定的蛋白质可以调节这些动态表面特性。主要的表面活性剂蛋白是一种已充分表征的脂质相关糖蛋白 SP 28-36 (28-36 kDa)。最近显示第二组非常疏水的蛋白质会影响表面活性剂磷脂的表面活性。我们从犬表面活性剂中分离出这组疏水蛋白，本文称为 SP 5-18 (5-18 kDa)，并通过 NH2 末端序列分析表明，该组中存在至少两种蛋白，SP 5-8 和 SP 18。我们从用基于 SP 18 NH2 末端氨基酸的寡核苷酸探针鉴定的 cDNA 的核苷酸序列中推导出了 SP 18 的完整氨基酸序列。从细胞外表面活性剂分离的蛋白质似乎是更大的前体蛋白质 (40 kDa) 的片段。 SP 18 的氨基酸序列具有明显的疏水性，并且包含两个可能的双层跨越结构域。我们已经证明，SP 18 和糖蛋白 SP 28-36 在促进磷脂表面膜的形成方面具有协同的钙依赖性作用。
Pulmonary surfactant is a lipid-rich material that promotes alveolar stability by lowering the surface tension at the air-fluid interface in the peripheral air spaces. The turnover of surfactant phospholipids in the alveolar space is fast, and several lines of evidence suggest there is rapid formation and replenishment of the phospholipid surface film during normal respiration. Specific proteins may regulate these dynamic surface properties. The predominant surfactant protein is a well-characterized, lipid-associated glycoprotein, SP 28-36 (28-36 kDa). A second group of very hydrophobic proteins has recently been shown to affect the surface activity of surfactant phospholipids. We have isolated this group of hydrophobic proteins, herein called SP 5-18 (5-18 kDa), from canine surfactant and have shown by NH2-terminal sequence analysis that at least two proteins, SP 5-8 and SP 18, are present in this group. We have derived the full amino acid sequence of SP 18 from the nucleotide sequence of the cDNAs identified with oligonucleotide probes that were bsed on the NH2-terminal amino acids of SP 18. The protein isolated from extracellular surfactant appears to be a fragment of a much larger precursor protein (40 kDa). The amino acid sequence of SP 18 is markedly hydrophobic and contains two possible bilayer-spanning domains. We have shown that SP 18 and the glycoprotein SP 28-36 have a cooperative, calcium-dependent action in promoting the formation of phospholipid surface films.