Probing single protein dynamics on liposome surfaces

TL;DR

This paper introduces LipoFRET, a fluorescence technique leveraging FRET to measure the position and dynamics of proteins on liposome surfaces with nanometer precision, enabling new insights into membrane-associated protein behavior.

Contribution

The study presents a novel fluorescence method, LipoFRET, capable of probing protein conformational dynamics on liposome surfaces with high spatial resolution.

Findings

LipoFRET accurately locates fluorophores relative to membranes.

Applied to {}-synuclein, it revealed dynamic conformational changes.

Provides quantitative data on protein-membrane interactions.

Abstract

It is crucial to measure position and conformational changes of a membrane-interacting protein relative to the membrane surface. This is however challenging because the thickness of a membrane is usually only about 4 nm. We developed a fluorescence method which makes use of the principle of FRET between a fluorophore and a cloud of quenchers encapsulated in a liposome, hence the name LipoFRET. LipoFRET can readily locate a fluorophore in different depths inside and at different heights above the membrane. We applied LipoFRET to study {\alpha}-synuclein, a key player in the pathology of Parkinson's disease. Our approach yielded quantita-tive information about the dynamics of different regions of {\alpha}-syn in lipid membranes, which has never been explored before.