Physical Chemistry I - Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Street 4a, 44227 Dortmund, Germany.
Soft Matter. 2021 Mar 21;17(11):3191-3206. doi: 10.1039/d0sm01934h. Epub 2021 Feb 23.
Various studies have described remarkable biological activities and surface-active properties of rhamnolipids, leading to their proposed use in a wide range of industrial applications. Here, we report on a study of the effects of monorhamnolipid RhaCC and dirhamnolipid RhaRhaCC incorporation into model membranes of varying complexity, including bacterial and heterogeneous model biomembranes. For comparison, we studied the effect of HAA (CC, lacking a sugar headgroup) partitioning into these membrane systems. AFM, confocal fluorescence microscopy, DSC, and Laurdan fluorescence spectroscopy were employed to yield insights into the rhamnolipid-induced morphological changes of lipid vesicles as well as modifications of the lipid order and lateral membrane organization of the model biomembranes upon partitioning of the different rhamnolipids. The partitioning of the three rhamnolipids into phospholipid bilayers changes the phase behavior, fluidity, lateral lipid organization and morphology of the phospholipid membranes dramatically, to what extent, depends on the headgroup structure of the rhamnolipid, which affects its packing and hydrogen bonding capacity. The incorporation into giant unilamellar vesicles (GUVs) of a heterogeneous anionic raft membrane system revealed budding of domains and fission of daughter vesicles and small aggregates for all three rhamnolipids, with major destabilization of the lipid vesicles upon insertion of RhaCC, and also formation of huge GUVs upon the incorporation of RhaRhaCC. Finally, we discuss the results with regard to the role these biosurfactants play in biology and their possible impact on applications, ranging from agricultural to pharmaceutical industries.
各种研究已经描述了鼠李糖脂的显著生物活性和表面活性特性，这导致它们被提议用于广泛的工业应用。在这里，我们报告了一项关于单鼠李糖脂 RhaCC 和二鼠李糖脂 RhaRhaCC 对不同复杂程度的模型膜（包括细菌和异质模型生物膜）影响的研究。为了进行比较，我们研究了 HAA（CC，缺乏糖头基）分配到这些膜系统中的效果。使用原子力显微镜、共聚焦荧光显微镜、差示扫描量热法和 Laurdan 荧光光谱法来深入了解鼠李糖脂诱导脂质囊泡形态变化以及不同鼠李糖脂分配对模型生物膜中脂质有序性和侧向膜组织的修饰。三种鼠李糖脂分配到磷脂双层中会极大地改变磷脂膜的相行为、流动性、侧向脂质组织和形态，其程度取决于鼠李糖脂的头基结构，这会影响其包装和氢键形成能力。将三种鼠李糖脂掺入异质阴离子筏模型生物膜系统的巨大单层囊泡 (GUV) 中，会导致所有三种鼠李糖脂的域出芽和子囊泡分裂以及小聚集体形成，而 RhaCC 的插入会极大地破坏脂质囊泡的稳定性，并且 RhaRhaCC 的掺入会形成巨大的 GUV。最后，我们将讨论这些结果与这些生物表面活性剂在生物学中的作用以及它们在从农业到制药等行业的应用中的可能影响有关。
