Immunoglobulin G glycopeptide profiling by matrix-assisted laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry

Anal Chem. 2010 Feb 1;82(3):1073-81. doi: 10.1021/ac9024413.

Abstract

Immunoglobulin G (IgG) fragment crystallizable (Fc) glycosylation is essential for Fc-receptor-mediated activities. Changes in IgG Fc glycosylation have been found to be associated with various diseases. Here we describe a high-throughput IgG glycosylation profiling method. Sample preparation is performed in 96-well plate format: IgGs are purified from 2 microL of human plasma using immobilized protein A. IgGs are cleaved with trypsin, and the resulting glycopeptides are purified by reversed-phase or hydrophilic interaction solid-phase extraction. Glycopeptides are analyzed by intermediate pressure matrix-assisted laser desorption ionization Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR-MS). Notably, both dihydroxybenzoic acid (DHB) and alpha-cyano-4-hydroxycinnamic acid (CHCA) matrixes allowed the registration of sialylated as well as nonsialylated glycopeptides. Data were automatically processed, and IgG isotype-specific Fc glycosylation profiles were obtained. The entire method showed an interday variation below 10% for the six major glycoforms of both IgG1 and IgG2. The method was found suitable for isotype-specific high-throughput IgG glycosylation profiling from human plasma. As an example we successfully applied the method to profile the IgG glycosylation of 62 human samples.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Cohort Studies
  • Female
  • Fourier Analysis
  • Glycopeptides / analysis*
  • Glycopeptides / isolation & purification
  • Glycosylation
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin G / chemistry
  • Immunoglobulin G / metabolism*
  • Immunoglobulin Subunits
  • Male
  • Middle Aged
  • Solid Phase Extraction
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / instrumentation
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods*
  • Staphylococcal Protein A / metabolism
  • Trypsin / metabolism

Substances

  • Glycopeptides
  • Immunoglobulin G
  • Immunoglobulin Subunits
  • Staphylococcal Protein A
  • Trypsin