title: Quantitative profiling of PE, MMPE, DMPE, and PC lipid species by multiple precursor ion scanning: a tool for monitoring PE metabolism.
abstract: We report a method for the simultaneous identification and quantification of phosphatidylethanolamine (PE), monomethyl-phosphatidylethanolamine (MMPE), dimethyl-phosphatidylethanolamine (DMPE), and phosphatidylcholine (PC) species in lipid extracts. The method employs a specific "mass-tag" strategy where DMPE, MMPE, and PE species are chemically methylated with deuterated methyliodide (CD(3)I) to produce PC molecules having class-specific mass offsets of 3, 6 and 9Da, respectively. The derivatized aminoglycerophospholipids release characteristic phosphorylcholine-like fragment ions having specific mass offsets that powers sensitive and quantitative analysis by multiple precursor ion scanning on a hybrid quadrupole time-of-flight mass spectrometer. Using the mass-tag strategy, we could for the first time determine the stoichiometric relationship between the biosynthetic intermediates MMPE and DMPE, and abundant PE and PC species in a single mass spectrometric analysis. We demonstrated the efficacy of the methodology by conducting a series of biochemical experiments using stable isotope labeled ethanolamine to survey the activities and substrate specificities of enzymes involved in PE metabolism in Saccharomyces cerevisiae. Finally, we benchmarked the mass-tag strategy by specific and sensitive profiling of intermediate MMPE and DMPE species in liver.
authors: Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
authors: Mesut
authors: M
authors: Bilgin
authors: Daniel F
authors: DF
authors: Markgraf
authors: Eva
authors: E
authors: Duchoslav
authors: Jens
authors: J
authors: Knudsen
authors: Ole N
authors: ON
authors: Jensen
authors: Anton I P M
authors: AI
authors: de Kroon
authors: Christer S
authors: CS
authors: Ejsing
mesh_terms: D000818:Animals; D003903:Deuterium / Q000378:metabolism; D019856:Ethanolamine / Q000378:metabolism; D007553:Isotope Labeling / Q000379:methods*; D050356:Lipid Metabolism; D008099:Liver / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D010713:Phosphatidylcholines / Q000032:analysis*; D010714:Phosphatidylethanolamines / Q000032:analysis*; D012441:Saccharomyces cerevisiae / Q000737:chemistry*; D013379:Substrate Specificity
chemical_list: D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D019856:Ethanolamine; D003903:Deuterium