Indicator displacement assays that detect bilayer membranes enriched in phosphatidylserine

Roger G. Hanshaw, Edward J. O'Neil, Meredith Foley, Rachael T. Carpenter, Bradley D. Smith
2005 Journal of Materials Chemistry  
Three indicator displacement assays are described for the detection of phosphatidylserine in a bilayer membrane. A series of Zn 2+ -dipicolylamine coordination compounds are used to bind selectively to the phosphatidylserine and act as a colorimetric chemosensing ensemble when combined with the UV-Vis indictor pyrocatechol violet. A similar displacement assay uses a coumarin methylsulfonate derivative as a fluorescent indicator, and a third assay involves quenching of calcein fluorescence by Cu
more » ... 2+ and subsequent fluorescence restoration upon addition of phosphatidylserine. In the best case, vesicle membranes containing as little as 5% phosphatidylserine could be detected under physiologically relevant conditions using as little as 10 mM sensing ensemble, and two of the three systems allow vesicles containing 50% phosphatidylserine to be detected by the naked eye.
doi:10.1039/b500522a fatcat:atyrwpnzofaajoxe62q5ljvk3m