Resolution of complex fluorescence spectra of lipids and nicotinic acetylcholine receptor by multivariate analysis reveals protein-mediated effects on the receptor's immediate lipid microenvironment

TL;DR

This study uses multivariate analysis to deconvolute complex fluorescence spectra of lipids and nicotinic acetylcholine receptors, revealing how proteins influence the receptor's surrounding lipid environment.

Contribution

It introduces a multivariate analysis approach to interpret overlapping fluorescence spectra in biological membranes, uncovering protein effects on lipid microenvironments.

Findings

FRET observed between protein and lipid probes.

Multivariate analysis successfully separated overlapping spectral signals.

Protein presence alters lipid microenvironment as shown by spectral changes.

Abstract

Analysis of fluorescent spectra from complex biological systems containing various fluorescent probes with overlapping emission bands is a challenging task. Valuable information can be extracted from the full spectra, however, by using multivariate analysis (MA) of measurements at different wavelengths. We applied MA to spectral data of purified Torpedo nicotinic acetylcholine receptor (AChR) protein reconstituted into liposomes made up of dioleoylphosphatidic acid (DOPA) and dioleoylphosphatidylcholine (DOPC) doped with two extrinsic fluorescent probes (NBD-cholesterol/pyrene-PC). Forster resonance energy transfer (FRET) was observed between the protein and pyrene-PC and between pyrene-PC and NBD-cholesterol, leading to overlapping emission bands. Partial least squares analysis was applied to ...