Cell membranes are known to exhibit non-uniform distribution of lipids and cholesterol, i.e., to form microdomain structures (lipid rafts) that serve as platforms for specific recruitment of proteins related to transportation and signal transduction. I focus on the reaction field such as lipid rafts to increase concentration of substrates. Recently, we demonstrated that a new flavin probe, composed of palmitoylated peptide nucleic acid (PNA) and its complementary PNA labeled with flavin, targets the liquid-ordered (lo) microdomains (i.e, mimicking rafts) and disrupts its interfaces to liquid-disordered (ld) microdomains of giant unilamellar vesicles (GUVs), and can be visualized by using confocal laser scanning microscopy. Surprisingly, the probe disrupted lo–ld interfaces as observed in the time-lapse images, in which vesiculations and aggregations of both probes, labeled PNA duplex and Texas Red–1,2-dipalmitoyl-<i>sn</i>-glycero-3-phosphoethanolamine (TR–DHPE, almost exclusively partitioned into the ld domain) appeared. From the control experiments with labeled DNA instead of labeled PNA showing that the lo domains remained stable enough to assess quantitative fluorescence analysis. Accordingly, we interpreted the vesiculations and probe aggregations may be induced by redistribution of PNA duplex and its forming large curvatures in lo–ld interfaces. Further studies to concentrate some probes at the interfaces will be also presented.

Probe aggregation into the interfaces between mimicking raft and non-raft domains, induced by peptide nucleic acid (PNA) duplexes

256th National Meeting (2018)

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