Comprehensive Quantitation Using Two Stable Isotopically Labeled Species and Direct Detection of N -Acyl Moiety of Sphingomyelin

In this study, a qualitative liquid chromatography-electrospray ionization tandem mass spectrometry (LC –ESI–MS/MS/MS) analysis is proposed in which CerPCho structures were assigned based on product ion spectra corresponding to sphingosylphosphorylcholine andN-acyl moieties. From MS/MS/MS analysis of CerPCho, we observed product ion spectra of theN-acyl fatty acids as [RCO2]− ions as well as sphingosylphosphorylcholine. A calibration curve for CerPCho was constructed using two stable isotopically labeled CerPCho species and then used to quantify the CerPCho species in HeLa cells as a proof-of-principle study. The present study proposes an accurate method for quantifying and assigning structures to each CerPCho species in crude biologic samples by LC –ESI–MS/MS/MS analysis.

Source: Lipids - August 2, 2017 Category: Lipidology Source Type: research