Fluorescent indolizine derivative YI-13 detects amyloid-β monomers, dimers, and plaques in the brain of 5XFAD Alzheimer transgenic mouse model
Fig 5
In vitro analysis of fluorescent YI-13 to detect its interaction with Aβ oligomers and dimers.
(A) A scheme of isolating oligomers from heterogeneous mixture of Aβ aggregates (50 μM). Through 100 kDa membrane filter, high molecular weight Aβ oligomers over 100 kDa were removed from the mixture of Aβ aggregates. The filtrate sample was applied to the 30 kDa filter to exclude low molecular weight Aβ aggregates. Only Aβ oligomers sized from 30 to 100 kDa were used for further experiment. The illustration was drawn using Adobe Photoshop software. (B-C) Fluorescence spectral scan of YI-13 (250 μM) when applied to Aβ. Blank indicates fluorescent intensities of YI-13 without Aβ. (B) Fluorescent analyses of YI-13 with the isolated Aβ oligomers. (C) Fluorescent analyses of YI-13 with the parallel Aβ dimer (25 μM). (D) Structure of synthesized parallel Aβ dimer with a lysine linker and spacer sequences, (GGGS)2. Abbreviations: FI = fluorescence intensity, AU = arbitrary unit.