TY - JOUR
T1 - HDL particles incorporate into lipid bilayers-a combined AFM and single molecule fluorescence microscopy study
AU - Plochberger, Birgit
AU - Röhrl, Clemens
AU - Preiner, Johannes
AU - Rankl, Christian
AU - Brameshuber, Mario
AU - Madl, Josef
AU - Bittman, Robert
AU - Ros, Robert
AU - Sezgin, Erdinc
AU - Eggeling, Christian
AU - Hinterdorfer, Peter
AU - Stangl, Herbert
AU - Schütz, Gerhard J.
N1 - Funding Information:
This work was supported by the Austrian Science Fund (FWF project Y250-B03, P20116-B11, P22838-B13, P29110-B21), the GEN-AU project of the Austrian Federal Ministry for Science and Research, the European Fund for Regional Development (EFRE, Regio 13) and the Federal State of Upper Austria. B.P. is a recipient of the Doc-fForte stipend of the Austrian Academy of Sciences. B.P. acknowledges the Austrian Science Fund Project P29110–B21, and the Austrian Research Promotion Agency Innovatives 2020–851455. JP acknowledges the European Fund for Regional Development (EFRE, Regio 13, IWB2020) and the Federal State of Upper Austria. E.S. is supported by EMBO long term (ALTF 636-2013) and Marie Skłodowska-Curie Intra-European Fellowships (MEMBRANE DYNAMICS-627088). C.E. and E.S. are supported by the Wolfson Foundation (ref. 18272), the Medical Research Council (MRC, grant number MC_UU_12010/unit programmes G0902418 and MC_UU_12025), MRC/BBSRC/ESPRC (grant number MR/K01577X/1), the Wellcome Trust (grant ref. 104924/14/Z/14), and internal University of Oxford funding (EPA Cephalosporin Fund and John Fell Fund).
Publisher Copyright:
© 2017 The Author(s).
PY - 2017/12/1
Y1 - 2017/12/1
N2 - The process, how lipids are removed from the circulation and transferred from high density lipoprotein (HDL)-a main carrier of cholesterol in the blood stream-to cells, is highly complex. HDL particles are captured from the blood stream by the scavenger receptor, class B, type I (SR-BI), the so-called HDL receptor. The details in subsequent lipid-transfer process, however, have not yet been completely understood. The transfer has been proposed to occur directly at the cell surface across an unstirred water layer, via a hydrophobic channel in the receptor, or after HDL endocytosis. The role of the target lipid membrane for the transfer process, however, has largely been overlooked. Here, we studied at the single molecule level how HDL particles interact with synthetic lipid membranes. Using (high-speed) atomic force microscopy and fluorescence correlation spectroscopy (FCS) we found out that, upon contact with the membrane, HDL becomes integrated into the lipid bilayer. Combined force and single molecule fluorescence microscopy allowed us to directly monitor the transfer process of fluorescently labelled amphiphilic lipid probe from HDL particles to the lipid bilayer upon contact.
AB - The process, how lipids are removed from the circulation and transferred from high density lipoprotein (HDL)-a main carrier of cholesterol in the blood stream-to cells, is highly complex. HDL particles are captured from the blood stream by the scavenger receptor, class B, type I (SR-BI), the so-called HDL receptor. The details in subsequent lipid-transfer process, however, have not yet been completely understood. The transfer has been proposed to occur directly at the cell surface across an unstirred water layer, via a hydrophobic channel in the receptor, or after HDL endocytosis. The role of the target lipid membrane for the transfer process, however, has largely been overlooked. Here, we studied at the single molecule level how HDL particles interact with synthetic lipid membranes. Using (high-speed) atomic force microscopy and fluorescence correlation spectroscopy (FCS) we found out that, upon contact with the membrane, HDL becomes integrated into the lipid bilayer. Combined force and single molecule fluorescence microscopy allowed us to directly monitor the transfer process of fluorescently labelled amphiphilic lipid probe from HDL particles to the lipid bilayer upon contact.
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U2 - 10.1038/s41598-017-15949-7
DO - 10.1038/s41598-017-15949-7
M3 - Article
C2 - 29162870
AN - SCOPUS:85034779677
SN - 2045-2322
VL - 7
JO - Scientific reports
JF - Scientific reports
IS - 1
M1 - 15886
ER -