Lipid raft is a microdomain being rich in cholesterol and sphingolipid and closely related to neurodegenerative diseases such as Alzheimer’s disease and prion disease. Hence the study on the physiological mechanism of lipid raft is helpful to reveal its biological role and its correlations with diseases. Two-photon fluorescence probe for lipid raft is a sharp tool to achieve this goal. A dicyanocarbazolylstilbene-derived two-photon fluorescence probe for lipid raft (DLR) was developed. Both DLR and lipid raft belong to D-π-A (donor-π-acceptor; π: C = C) type rigid planar molecule, and contain four fused carbon rings (one five-membered ring and three six-membered ring), and bear a long carbon chain (C₈H₁₇). The excellent comparability between the rigid plane of the probe molecule and the rigid lipid raft could significantly enhance the specific affinity to lipid rafts. DLR’s maximum emission wavelength increased with medium polarity while its fluorescence intensity (FI) augmented with viscosity, and FI in DPPC (dipalmitoylphosphatidylcholine) was 20 times higher than that in DOPC (dioleoylphosphatidylcholine). DLR’s fluorescence lifetime in DPPC was more than 2.2 times longer than that in DOPC. These indicate that DLR can distinguish DPPC from DOPC. Φδs of DLR in DPPC and DOPC were 1350 GM and 67 GM, respectively. DLR can image lipid raft distribution in cells and tissues.

Graphic abstract

中文翻译：

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一种双光子荧光脂筏探针，来源于二氰芪，类似于胆固醇的结构

脂筏是一个富含胆固醇和鞘脂的微结构域，与阿尔茨海默病、朊病毒病等神经退行性疾病密切相关。因此，对脂筏生理机制的研究有助于揭示其生物学作用及其与疾病的相关性。脂筏双光子荧光探针是实现这一目标的利器。开发了用于脂筏（DLR）的二氰基咔唑基芪衍生的双光子荧光探针。DLR和脂筏都属于D-π-A（供体-π-受体；π：C=C）型刚性平面分子，含有四个稠合碳环（一个五元环和三个六元环），并带有长碳链（C ₈ H ₁₇）。探针分子的刚性平面与刚性脂筏之间极好的可比性可以显着增强对脂筏的特异性亲和力。DLR的最大发射波长随极性增大而增大，荧光强度(FI)随粘度增大而增大，DPPC(dipalmitoylphosphatidylcholine)中的FI比DOPC(dioleoylphosphatidylcholine)高20倍。DLR在DPPC中的荧光寿命比在DOPC中长2.2倍以上。这些表明 DLR 可以区分 DPPC 和 DOPC。DPPC 和 DOPC 中 DLR 的Φδ s 分别为 1350 GM 和 67 GM。DLR 可以对细胞和组织中的脂筏分布进行成像。

图形摘要