Harishchandra Rakesh Kumar, Sachan Amit Kumar, Kerth Andreas, Lentzen Georg, Neuhaus Thorsten, Galla Hans-Joachim
Institute of Biochemistry, Westfälische Wilhelms Universität, Wilhelm Klemm Str. 2, 48149 Münster, Germany.
Biochim Biophys Acta. 2011 Dec;1808(12):2830-40. doi: 10.1016/j.bbamem.2011.08.022. Epub 2011 Aug 22.
Ectoine and hydroxyectoine belong to the family of compatible solutes and are among the most abundant osmolytes in nature. These compatible solutes protect biomolecules from extreme conditions and maintain their native function. In the present study, we have investigated the effect of ectoine and hydroxyectoine on the domain structures of artificial lung surfactant films consisting of dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG) and the lung surfactant specific surfactant protein C (SP-C) in a molar ratio of 80:20:0.4. The pressure-area isotherms are found to be almost unchanged by both compatible solutes. The topology of the fluid domains shown by scanning force microscopy, which is thought to be responsible for the biophysical behavior under compression, however, is modified giving rise to the assumption that ectoine and hydroxyectoine are favorable for a proper lung surfactant function. This is further evidenced by the analysis of the insertion kinetics of lipid vesicles into the lipid-peptide monolayer, which is clearly enhanced in the presence of both compatible solutes. Thus, we could show that ectoine and hydroxyectoine enhance the function of lung surfactant in a simple model system, which might provide an additional rationale to inhalative therapy.
四氢嘧啶和羟基四氢嘧啶属于相容性溶质家族，是自然界中最丰富的渗透溶质之一。这些相容性溶质可保护生物分子免受极端条件影响并维持其天然功能。在本研究中，我们研究了四氢嘧啶和羟基四氢嘧啶对由二棕榈酰磷脂酰胆碱（DPPC）、二棕榈酰磷脂酰甘油（DPPG）和肺表面活性剂特异性表面活性蛋白C（SP-C）以80:20:0.4的摩尔比组成的人工肺表面活性剂膜的结构域结构的影响。发现这两种相容性溶质几乎不会改变压力-面积等温线。然而，扫描力显微镜显示的流体结构域的拓扑结构（据认为其负责压缩下的生物物理行为）发生了改变，这引发了一种假设，即四氢嘧啶和羟基四氢嘧啶有利于肺表面活性剂发挥正常功能。脂质囊泡插入脂质-肽单层的动力学分析进一步证明了这一点，在两种相容性溶质存在的情况下，脂质囊泡的插入动力学明显增强。因此，我们可以证明，在一个简单的模型系统中，四氢嘧啶和羟基四氢嘧啶可增强肺表面活性剂的功能，这可能为吸入疗法提供额外的理论依据。
