The conversion of ceramide into sphingomyelin (SM) was only recently considered in relation to cancer. Overexpression of the CERT protein, responsible for a highly specific inter-organelle ceramide transfer step along the de novo SM synthesis pathway, has been associated with multi-drug resistance of cancer cells. Identification of new CERT antagonists may therefore lead to potential resensitizing agents. This work describes the first attempt to design a ceramide-based fluorescent probe optimised to evaluate the binding of potential CERT ligands. A prototypical structure with an ω-labelled sphingosine backbone was selected. Its possible recognition mode by CERT was first evaluated by means of a precursory molecular modelling study. Three derivatives with various amide chain lengths were prepared and tested. The binding efficiency was shown to be proportional to the lipophilicity of the acyl moiety. The best compound bearing a C16 amide fragment was used to implement a practical binding experiment. Facile assessment of the recognition by the CERT START domain of various structures was thus ensured. Metabolism and imaging experiments were also used to illustrate the capacity of the proposed fluorescent ceramide analogue to mimic the natural ceramide cellular behaviour. This work led to the synthesis and evaluation as an efficient CERT START domain ligand of a ω-biotinylated ceramide, a potential probe to develop the screening of new CERT antagonists.
神经酰胺向鞘
磷脂(SM)的转化直到最近才被认为与癌症有关。CERT 蛋白负责从头合成 SM 途径中一个高度特异的细胞器间神经酰胺转移步骤,它的过表达与癌细胞的多重耐药性有关。因此,鉴定新的 CERT 拮抗剂可能会带来潜在的抗敏药物。这项研究首次尝试设计一种基于陶瓷酰胺的荧光探针,并对其进行了优化,以评估潜在 CERT
配体的结合情况。我们选择了一种具有ω标记鞘
磷脂骨架的原型结构。首先通过先导分子建模研究评估了 CERT 可能的识别模式。制备并测试了三种具有不同酰胺链长度的衍
生物。结合效率与酰基的亲脂性成正比。含有 C16
氨基酸片段的最佳化合物被用于实际结合实验。这样就确保了对 CERT START 结构域识别各种结构的便捷评估。新陈代谢和成像实验也用来说明拟议的荧光神经酰胺类似物模仿天然神经酰胺细胞行为的能力。通过这项工作,我们合成并评估了一种ω-
生物素化神经酰胺的高效 CERT START 结构域
配体,它是筛选新型 CERT 拮抗剂的潜在探针。