Abstract
The Plasma membrane consists of two highly asymmetric layers and is compartmentalized into small heterogeneities (nanodomains) whose mutual position within the bilayer is determined by strong interleaflet interactions. Regarding nanodomain organization four scenarios have been considered: perfect registration across the membrane, independent distribution, anti-registration (nanodomains in the opposing leaflets are repelled), or presence in only one membrane leaflet.
Due to nanodomain characteristics, it is highly challenging to distinguish these scenarios from each other. We have therefore developed a powerful method called MC-FRET (Förster resonance energy transfer analyzed by Monte-Carlo simulations) that can determine the size, concentration, and organization of lipid rafts.
The aim is to find the limits of MC-FRET by discovering membrane parameters responsible for yielding sufficient/optimal resolution. We generated and analyzed in-silico time-resolved fluorescence decays for a large set of virtual as well as real donor/acceptor pairs with variously distributed nanodomains to identify conditions that gave satisfactory or unsatisfactory resolution.
Overall, FRET is a robust method that under specific conditions reveals otherwise difficult-to-reach characteristics of membrane lipid nanodomains