tailieunhanh - Báo cáo khoa học: Detergent-resistant membrane fractions contribute to the total 1 H NMR-visible lipid signal in cell

Leukocytes and other cells show an enhanced intensity of mobile lipid in their 1 H NMR spectra under a variety of conditions include stimulation, which has recently been shown to involve detergent-resistant, plasma membranedomains (DRMs)oftencalled there ismuchspeculationsurrounding theoriginof cellularNMR-visible lipid, we analysed subcellular fractions, including DRMs, by NMR spectroscopy. | Eur. J. Biochem. 270 2091-2100 2003 FEBS 2003 doi Detergent-resistant membrane fractions contribute to the total 1H NMR-visible lipid signal in cells Lesley C. Wright1 Julianne T. Djordjevic2 Stephen D. Schibeci2 Uwe Himmelreich5 Nick Muljadi3 4 Peter Williamson2 and Garry W. Lynch3 4 1 Centre for Infectious Diseases and Microbiology Institute of Clinical Pathology Medical Research 2Institute of Immunology Allergy Research 3 Centre for Virus Research Westmead Millennium Institute the Cellular and Molecular Pathology Research Unit Department of Oral Pathology and Oral Medicine Westmead Hospital Dental School and 4National Centre for HIV Virology Research University of Sydney Westmead Hospital NSW Australia 5Institute for Magnetic Resonance Research Westmead Royal North Shore Hospital St. Leonards NSW Australia Leukocytes and other cells show an enhanced intensity of mobile lipid in their 1H NMR spectra under a variety of conditions. Such conditions include tiimulaiion. which Inis recently been shown to involve detergent-resistant plasma membrane domains DRMs often called lipid rafts. As hiere is much speculation surrounding the origin of cellular NMR-visible lipid we analysed subcellular fractions including DRMs by NMR spectroscopy. We demonstrated that DRMs isolated by density gradient centrifugation from lymphoid CEM-T4 stimulated Jurkat cells and monocytoid THP-1 cells produced NMR-visible lipid signals. Large scale subfractionation of THP-1 cells determined that while cytoplasmic lipid droplets constituted much of the total NMR-visible lipid the contribution of DRMs was and quanitative lipid analyses revealed that DRMs and lipid droplets differed in their lipid composition. DRMs were enriched in cholesterol and ganglioside GM1 and contained relatively unsaturated fatty acids compared with the lipid droplets. Both iipid dopoets tod DR Ms contained neutral lipids triacylgycdrols cholesterol ester fatty .