A Novel Visible Range FRET Probe for Monitoring Acid Sphingomyelinase Activity in Living Cells
C. Oliver Kappe, Zainelabdeen H. Mohamed, Eyad Naser, Alexander Carpinteiro, Christoph Arenz
Abstract
Activity of acid sphingomyelinase has been implicated in a number of diseases like acute lung injury, sepsis or metastasis of melanoma cells. Here, we present a sphingomyelinase FRET probe based on FAM/BODIPY dyes for real-time monitoring of acid sphingomyelinase. The probe gives rise to a tremendous increase in fluorescence of the fluorescein FRET donor upon cleavage and we show that this is, to a significant part, due to cleavage-associated phase transition, suggesting a more systematic consideration of such effects for future probe development. The probe allows for the first time to monitor relative sphingomyelinase activities of intact living cells by flow cytometry.