Sponsor
This material is based on research sponsored by Air Force Research Laboratory under agreement number FA8650-05-1-5041, the Office of Naval Research under agreement number 00014-07-1-0457, and the NIH under 1R15GM088960.
Document Type
Post-Print
Publication Date
4-2010
Subjects
Atherosclerosis, Lecithin, Low density lipoproteins, C-reactive protein, Biomimicry
Abstract
Lipid-coated metal nanoparticles are developed here as a mimic of low-density lipoprotein (LDL) particles and used to study C-reactive protein (CRP) binding to highly curved lipid membranes. A 12 nm shift in the localized surface plasmon resonance (LSPR) was observed when CRP was added to the lipid-coated gold nanoparticles. Transmission electron microscopy (TEM) revealed that CRP induced a structural change to the lipids, resulting in clusters of nanoparticles. This clustering provides a visualization of how CRP could cause the aggregation of LDL particles, which is a key step in atherosclerosis. The cluster formation and resultant LSPR shift requires the presence of both CRP and calcium. Fluorescence anisotropy, using a CRP-specific, fluorophore-labeled aptamer confirmed that CRP was bound to the lipid-coated nanoparticles. An increase in the fluorescence anisotropy (Δr = +0.261 ± 0.004) of the aptamer probe occurs in the presence of CRP, PC-coated nanoparticles, and calcium. Subsequent sequestration of calcium by EDTA leads to a decrease in the anisotropy (Δr = -0.233 ± 0.011), however, there is no change in the LSPR and no change to the cluster structure observed by TEM. This indicates that CRP binds to the PC membrane on the nanoparticle surface reversibly through a calcium bridging mechanism while changing the underlying membrane structure irreversibly as a result of binding.
DOI
10.1021/jp911617q
Persistent Identifier
http://archives.pdx.edu/ds/psu/20519
Citation Details
Mackiewicz, Marilyn R.; Hodges, Heather L.; and Reed, Scott M., "C - Reactive Protein Induced Rearrangement of Phosphatidylcholine on Nanoparticle Mimics of Lipoprotein Particles" (2010). Chemistry Faculty Publications and Presentations. 191.
http://archives.pdx.edu/ds/psu/20519
Description
This is the author’s version of a work that was accepted for publication in the Journal of Physical Chemistry B. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Journal of Physical Chemistry B, 2010 Apr 29; 114(16): 5556–5562 and can be found online at: https://dx.doi.org/10.1021/jp911617q