Cover Picture: Development of a Novel FRET Probe for the Real‐Time Determination of Ceramidase Activity (ChemBioChem 9/2013)

Abstract

The cover picture shows a doubly labeled ceramide analogue developed by C. Arenz et al. (see the paper on ). Two fluorescent dyes (Nile Red and NBD) form an efficient FRET pair, which is destroyed upon cleavage of the ceramide by the acidic or neutral ceramidases. In contrast to simple quenched or turn‐on probes, the substrate design not only allows homogenous ceramidase assays (top left), but also ratio imaging (top right). The photobleaching experiment in HeLa cells shown at the bottom revealed almost complete FRET in a cellular environment. In this experimental setting, the FRET probe is trapped in the Golgi apparatus without cleavage by cellular ceramidases. In future experiments the probe might be used in quantitative in‐situ enzymatic assays in real‐time to elucidate the role of ceramidases in lipid signaling.