出版社：American Society for Biochemistry and Molecular Biology
摘要：Glycerophosphoethanolamine (GPEtn) and glycerophosphoserine(GPSer) lipids were reacted with a multiplexed set of differentiallyisotopically enriched N-methylpiperazine acetic acid N-hydroxysuccinimideester reagents, which place isobaric mass labels at a primaryamino group. The resulting derivatized aminophospholipids wereisobaric and chromatographically indistinguishable but yieldedpositive reporter ions (m/z 114 or 117) after collisional activationthat could be used to identify and quantify individual membersof the multiplex set. The chromatographic and mass spectrometricresponse of N-methylpiperazine amide-tagged aminophospholipidswas probed using glycerophosphoethanolamine and glycerophosphoserinelipid standards. The [M+H]+ of each tagged aminophospholipidshifted 144 Da, and during collision-induced dissociation themajor fragmentation ion was either m/z 114 or 117. This modeof detecting aminophospholipids was useful for an unbiased analysisof plasmalogen GPEtn lipids. Molecular species information onthe esterified fatty acyl substituents was obtained by collisionalactivation of the [M-H]– ions.
The isotope-tagged reagents were used to assess changes in thedistribution of GPEtn lipids after exposure of liposomes madefrom phospholipids extracted from RAW 264.7 cells to Cu2+/H2O2to illustrate the ability of these reagents to aid in the massspectrometric identification of aminophospholipid changes thatoccur during biological stimuli.Supplementary key words glycerophosphoethanolamine lipids • glycerophosphoserine lipids • electrospray • tandem mass spectrometry • lipid oxidation
