Nakahara Hiromichi, Shibata Osamu
Department of Biophysical Chemistry, Graduate School of Pharmaceutical Sciences, Nagasaki International University.
J Oleo Sci. 2014;63(11):1159-68. doi: 10.5650/jos.ess14105. Epub 2014 Oct 7.
Mammalian lungs are covered with lipid-protein complexes or pulmonary surfactants. In this work, which aimed towards the less expensive production of artificial pulmonary surfactants, we produced surfactants composed of egg yolk lecithin (eggPC), palmitic acid, and hexadecanol (= 0.30/0.35/0.35, mol/mol/mol ) containing different amounts of Hel 13-5 (NH2-KLLKLLLKLWLKLLKLLL-COOH) as a substitute for the proteins in native pulmonary surfactants. Surface pressure (π)-molecular area (A) and surface potential (DV)-A isotherms of the mixtures were measured via the Wilhelmy and ionizing (241)Am electrode methods, respectively. The interactions between the lipid components and Hel 13-5 led to variations in the surface pressure caused by the expulsion of fluid components from the surface. Furthermore, the π-A and DV-A isotherms featured large hysteresis loops for the surfactant that contained a small amount of Hel 13-5 during compression and successive expansion cycling. To elucidate the morphology, the phase behavior was visualized in situ at the air-water interface by means of fluorescence microscopy; the images suggested less effective interactions between Hel 13-5 and the unsaturated PC in eggPC despite the similarity of their monolayer properties.
哺乳动物的肺被脂质 - 蛋白质复合物或肺表面活性剂所覆盖。在这项旨在以较低成本生产人工肺表面活性剂的研究中，我们制备了由蛋黄卵磷脂（eggPC）、棕榈酸和十六醇（= 0.30/0.35/0.35，摩尔/摩尔/摩尔）组成的表面活性剂，其中含有不同量的Hel 13 - 5（NH2 - KLLKLLLKLWLKLLKLLL - COOH），以替代天然肺表面活性剂中的蛋白质。分别通过威廉米方法和电离（241）Am电极方法测量了混合物的表面压力（π）-分子面积（A）和表面电势（DV）-A等温线。脂质成分与Hel 13 - 5之间的相互作用导致表面流体成分排出，从而引起表面压力的变化。此外，对于在压缩和连续膨胀循环过程中含有少量Hel 13 - 5的表面活性剂，其π - A和DV - A等温线具有较大的滞后环。为了阐明形态，通过荧光显微镜在空气 - 水界面原位观察相行为；图像表明，尽管Hel 13 - 5与eggPC中的不饱和PC具有相似的单分子层性质，但它们之间的相互作用效率较低。
