Department of Chemistry , Lehigh University , Bethlehem , Pennsylvania 18015 , United States.
Langmuir. 2019 Sep 3;35(35):11542-11549. doi: 10.1021/acs.langmuir.9b01535. Epub 2019 Aug 22.
Fluorescent lipid probes are commonly used to label membranes of cells and model membranes like giant vesicles, liposomes, and supported lipid bilayers (SLB). Here, we show that excitation of fluorescent lipid probes with BODIPY-like conjugates results in a significant acceleration of the rupture and SLB formation process for unsaturated phospholipid vesicles on SiO surfaces. The resulting SLBs also have smaller measured masses, which is indicative of a reduction in membrane thickness and/or membrane density. The excitation of fluorescent probes with NBD and Texas Red conjugates does not accelerate the SLB formation process. In the absence of fluorescent probes or light, the inclusion of oxidized phospholipids also accelerates SLB formation. The excitation-induced acceleration caused by BODIPY-like probes is eliminated when the probes are present with saturated phospholipids not susceptible to oxidation, and it is attenuated when a lipophilic antioxidant (α-tocopherol) is present. These results suggest that BODIPY-phospholipid conjugates are photosensitizers, and their excitation causes oxidation of lipid membranes, which significantly alters membrane properties.
荧光脂质探针常用于标记细胞膜和模型膜，如巨囊泡、脂质体和支撑脂质双层（SLB）。在这里，我们表明，用 BODIPY 样缀合物激发荧光脂质探针会显著加速不饱和磷脂囊泡在 SiO 表面上的破裂和 SLB 形成过程。所得的 SLB 也具有更小的测量质量，这表明膜厚度和/或膜密度降低。用 NBD 和 Texas Red 缀合物激发荧光探针不会加速 SLB 的形成过程。在没有荧光探针或光的情况下，氧化磷脂的存在也会加速 SLB 的形成。当存在对氧化不敏感的饱和磷脂且不存在亲脂性抗氧化剂（α-生育酚）时，BODIPY 样探针引起的激发诱导的加速被消除，当存在亲脂性抗氧化剂（α-生育酚）时，这种加速被减弱。这些结果表明，BODIPY-磷脂缀合物是光敏剂，其激发会导致脂质膜氧化，从而显著改变膜性质。
