Dimeric N-terminal segment of human surfactant protein B (dSP-B(1-25)) has enhanced surface properties compared to monomeric SP-B(1-25).
Dimeric N-terminal segment of human surfactant protein B (dSP-B(1-25)) has enhanced surface properties compared to monomeric SP-B(1-25).
复制标题
与单体 SP-B(1-25) 相比，人表面活性剂蛋白 B (dSP-B(1-25)) 的二聚体 N 末端片段具有增强的表面特性。
DOI：
10.1016/s0006-3495(00)76299-0
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Haagsman,HP
中科院分区：
文献类型：
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作者：
Veldhuizen,EJ;Waring,AJ;Walther,FJ;Batenburg,JJ;vanGolde,LM;Haagsman,HP
表面活性蛋白B(SP-B)是由肺泡II型细胞产生的一种17 kDa的二聚体蛋白。它的主要功能是通过将脂质插入肺的气/液界面来降低表面张力。SP-B的功能可被基于SP-B N端序列的25个氨基酸组成的多肽SP-B1-25所模拟。我们合成了该多肽的二聚体版本，DSP-B1-25，并对两个多肽的表面活性进行了测试。SP-B1-25和DSP-B1-25均表现出良好的脂类混合和吸附活性。该二聚肽在压力驱动型气泡表面测定仪上显示出与天然SP-B相当的活性。在不含蛋白质的循环过程中，涂布表面膜的最小表面张力稳定在接近零的水平，而含有SP-B1-250的膜在压缩过程中会从界面上丢失物质。我们认为，需要多肽的二聚化来创建一个附着在单分子层上的脂库，当气/液界面膨胀时，新材料可以从该库进入表面膜。SP-B的二聚态在体内也可以发挥同样的作用。
Surfactant protein B (SP-B) is a 17-kDa dimeric protein produced by alveolar type II cells. Its main function is to lower the surface tension by inserting lipids into the air/liquid interface of the lung. SP-B's function can be mimicked by a 25-amino acid peptide, SP-B1–25, which is based on the N-terminal sequence of SP-B. We synthesized a dimeric version of this peptide, dSP-B1–25, and the two peptides were tested for their surface activity. Both SP-B1–25and dSP-B1–25showed good lipid mixing and adsorption activities. The dimeric peptide showed activity comparable to that of native SP-B in the pressure-driven captive bubble surfactometer. Spread surface films led to stable near-zero minimum surface tensions during cycling while protein free, and films containing SP-B1–25lost material from the interface during compression. We propose that dimerization of the peptide is required to create a lipid reservoir attached to the monolayer from which new material can enter the surface film upon expansion of the air/liquid interface. The dimeric state of SP-B can fulfill the same function in vivo.