Quantifying lipid contents in enveloped virus particles with plasmonic nanoparticles.
Phosphatidylserine (PS) and monosialotetrahexosylganglioside (GM1 ) are examples of two host-derived lipids in the membrane of enveloped virus particles that are known to contribute to virus attachment, uptake, and ultimately dissemination. A quantitative characterization of their contribution to the functionality of the virus requires information about their relative concentrations in the viral membrane. Here, a gold nanoparticle (NP) binding assay for probing relative PS and GM1 lipid concentrations in the outer leaflet of different HIV-1 and Ebola virus-like particles (VLPs) using sample sizes of less than 3 × 10(6) particles is introduced. The assay evaluates both scattering intensity and resonance wavelength, and determines relative NP densities through plasmon coupling as a measure for the target lipid concentrations in the NP-labeled VLP membrane. A correlation of the optical observables with absolute lipid contents is achieved by calibration of the plasmon coupling-based methodology with unilamellar liposomes of known PS or GM1 concentration. The performed studies reveal significant differences in the membrane of VLPs that assemble at different intracellular sites and pave the way to an optical quantification of lipid concentration in virus particles at physiological titers.
Department of Chemistry and the Photonics Center, Boston University, Boston, MA, 02215, USA.
Amin
A
Feizpour
Xinwei
X
Yu
Hisashi
H
Akiyama
Caitlin M
CM
Miller
Ethan
E
Edmans
Suryaram
S
Gummuluru
Björn M
BM
Reinhard
D002138:Calibration; D008055:Lipids / Q000032:analysis*; D008081:Liposomes; D053758:Nanoparticles; D014771:Virion / Q000737:chemistry*
D008055:Lipids; D008081:Liposomes
bioplasmonics; lipid quantification; plasmon coupling; viral lipidomics