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Chemical Imaging of Cholesterol and Sphingolipid Distribution in the Plasma Membranes of Fibroblast Cells
Author(s) -
Kraft Mary L,
Frisz Jessica F.,
Klitzing Haley A.,
Lou Kaiyan,
Lizunov Vladimir,
Zimmerberg Joshua,
Weber Peter K.
Publication year - 2012
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.26.1_supplement.601.5
Subject(s) - sphingolipid , membrane , cholesterol , lipid raft , chemistry , resolution (logic) , biophysics , plasma , biological membrane , microbiology and biotechnology , biochemistry , biology , physics , quantum mechanics , artificial intelligence , computer science
Cholesterol‐ and sphingolipid‐enriched membrane microdomains, which are referred to as lipid rafts, appear to mediate important biological functions. Yet, the distributions of cholesterol and sphingolipids within the plasma membrane remain poorly defined. The goal of this work is to use high‐resolution secondary ion mass spectrometry (SIMS) to directly image the distributions of cholesterol and sphingolipids within the plasma membranes of fibroblast cells. In our approach, we metabolically labeled the cells so that the cellular sphingolipids contained nitrogen‐15, and the cellular cholesterol contained oxygen‐18. We then employed a SIMS instrument designed for high‐resolution isotopic imaging of surfaces (Cameca NanoSIMS 50) to visualize the distributions of 18 O‐cholesterol and 15 N‐sphingolipids in the plasma membrane by mapping the 18 O‐enrichment and 15 N‐enrichment, respectively, on the cell surface (top <5 nm) with a lateral resolution of approximately 90 nm. Whether the cholesterol and sphingolipids were heterogeneously distributed and co‐localized within the plasma membrane was quantitatively assessed. Our data demonstrates that lipids within the plasma membrane are spatially organized on length scales that range from two hundred nanometers to a few micrometers. This research was supported by the National Science Foundation under CHE – 1058809 and a Career Award at the Scientific Interface from the Burroughs Wellcome Fund.