Electrospray ionization mass spectroscopic analysis of human erythrocyte plasma membrane phospholipids.
Electrospray ionization mass spectrometry (ESI-MS) was utilized for the structural determination and quantitative analysis of individual phospholipid molecular species from subpicomole amounts of human erythrocyte plasma membrane phospholipids. The sensitivity of ESI-MS was 2-3 orders of magnitude greater than that achievable with fast-atom bombardment mass spectrometry (FAB-MS). Phospholipid structure determination and quantitative analysis with ESI-MS can be performed directly from chloroform extracts of biologic samples, obviating the need for prior chromatographic separation of phospholipid classes which has been necessary in FAB-MS phospholipid analyses. Furthermore, ESI-MS is uncomplicated by differential fragmentation of molecular ions and idiosyncratic surface desorption, allowing the quantitation of phospholipids with coefficients of determination (r2) > 0.99 and accuracies > 95%. More than 50 human erythrocyte plasma membrane phospholipid constituents were identified by direct ESI-MS analysis of chloroform extracts of plasma membranes derived from the equivalent of < 1 microliter of whole blood. The major ethanolamine glycerophospholipid subclass in erythrocyte plasma membranes was plasmenylethanolamine that was highly enriched in polyunsaturated fatty acids at the sn-2 position. Collectively, these results demonstrate that ESI-MS of phospholipids is an enabling strategy for the direct structural determination and quantitative analysis of subpicomole amounts of phospholipids from biologic samples.
Han
X
X
Department of Internal Medicine, Washington University School of Medicine, St. Louis, MO 63110.
Gross
R W
RW
D004910:Erythrocyte Membrane / Q000737:chemistry*; D006801:Humans; D013058:Mass Spectrometry; D008563:Membrane Lipids / Q000097:blood* / Q000737:chemistry; D010743:Phospholipids / Q000097:blood* / Q000737:chemistry; D012680:Sensitivity and Specificity; D016339:Spectrometry, Mass, Fast Atom Bombardment; D018629:Spectrometry, Mass, Secondary Ion / Q000379:methods
D008563:Membrane Lipids; D010743:Phospholipids