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Towards understanding how lipid variations and membrane proteins may influence the biophysical chemistry of biomembranes
Author(s) -
Heikal Ahmed A
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.689.2
Subject(s) - membrane , endocytosis , förster resonance energy transfer , exocytosis , vesicle , chemistry , fluorescence correlation spectroscopy , membrane biophysics , biophysics , lipid bilayer , membrane fluidity , biological membrane , membrane protein , cell membrane , microbiology and biotechnology , fluorescence , biochemistry , cell , biology , molecule , physics , organic chemistry , quantum mechanics
Biomembranes in living cells are complex, heterogeneous and dynamic systems that regulate numerous biological processes such as cell signaling, endocytosis and exocytosis, and protein trafficking. Cholesterol‐rich lipid domains have been hypothesized to exist in a liquid‐ordered phase and play an important role in cellular functions. Yet, these direct observations of these lipid domains in the plasma membrane of living cell remain elusive. In addition, the relevance of model membranes to elucidate the structure‐function relationship of cellular membranes has been debated recently. Here, we test the hypothesis that cholesterol diffuses as a complex with other lipids in membranes, both model and natural ones. We also examine the role of lipid variation and proteins on the biophysical properties on biomembranes using comparative studies on giant unilamellar vesicles (GUVs) and plasma membrane vesicles (GPMVs) isolated from Hs578Bst living cells using newly developed Bodipy‐cholesterol derivatives. The fluorescence dynamics assay used here includes two‐photon fluorescence lifetime imaging, fluorescence resonance energy transfer, and fluorescence polarization as well as correlation spectroscopy. Our comparative studies on GUVs and GPMVs serve as a platform to test our understanding of lipid‐lipid and lipid‐protein interactions in the plasma membrane.