Xu J J, Richardson C, Ford C, Spencer T, Yao L J, Mackie G, Hammond G, Possmayer F
Department of Obstetrics & Gynaecology, University of Western Ontario, London, Canada.
Biochem Biophys Res Commun. 1989 Apr 14;160(1):325-32. doi: 10.1016/0006-291x(89)91659-8.
Pulmonary surfactant contains phospholipids including dipalmitoyl-phosphatidylcholine and three surfactant-associated proteins designated SP-A, SP-B and SP-C. A cDNA for rabbit SP-B has been isolated from a fetal (30 days gestation) rabbit lung cDNA library constructed in lambda gt11. The cDNA and deduced amino acid sequences show strong homology with the cDNAs and predicted 40 kDa proproteins for human and canine SP-B. Strong homology is also observed with the amino acid sequences directly determined for the mature 8 kDa bovine and porcine SP-B isolated from lung lavage. SP-B is remarkable for its high cysteine and proline content and for the hydrophobic nature of the organic solvent-soluble, mature protein. In vitro translation of sense but not antisense RNA transcribed from the cDNA led to the production of 40 kDa and 32 kDa proteins. These proteins were immunoprecipitated by an antibody raised against bovine SP-B. Northern blot analysis revealed the mRNA for rabbit SP-B appears in fetal rabbit lung late in gestation and falls slightly in the neonate.
肺表面活性物质包含磷脂，包括二棕榈酰磷脂酰胆碱以及三种与表面活性物质相关的蛋白，分别命名为SP-A、SP-B和SP-C。已从构建于λgt11的妊娠30天的胎兔肺cDNA文库中分离出兔SP-B的cDNA。该cDNA及其推导的氨基酸序列与人及犬SP-B的cDNA和预测的40 kDa前体蛋白具有高度同源性。从肺灌洗中分离出的成熟8 kDa牛和猪SP-B的直接测定氨基酸序列也显示出高度同源性。SP-B以其高半胱氨酸和脯氨酸含量以及有机溶剂可溶的成熟蛋白的疏水性而著称。从该cDNA转录的正义RNA而非反义RNA的体外翻译导致产生了40 kDa和32 kDa的蛋白。这些蛋白被针对牛SP-B产生的抗体免疫沉淀。Northern印迹分析显示，兔SP-B的mRNA在妊娠后期出现在胎兔肺中，在新生兔中略有下降。
