title: Automated annotation and quantitation of glycans by liquid chromatography/electrospray ionization mass spectrometric analysis using the MultiGlycan-ESI computational tool.
abstract: BACKGROUND
  Liquid chromatography/mass spectrometry (LC/MS) is currently considered to be a conventional glycomics analysis strategy due to the high sensitivity and ability to handle complex biological samples. Interpretation of LC/MS data is a major bottleneck in high-throughput glycomics LC/MS-based analysis. The complexity of LC/MS data associated with biological samples prompts the needs to develop computational tools capable of facilitating automated data annotation and quantitation.
  
  
  METHODS
  An LC/MS-based automated data annotation and quantitation software, MultiGlycan-ESI, was developed and utilized for glycan quantitation. Data generated by the software from LC/MS analysis of permethylated N-glycans derived from fetuin were initially validated by manual integration to assess the performance of the software. The performance of MultiGlycan-ESI was then assessed for the quantitation of permethylated fetuin N-glycans analyzed at different concentrations or spiked with permethylated N-glycans derived from human blood serum.
  
  
  RESULTS
  The relative abundance differences between data generated by the software and those generated by manual integration were less than 5%, indicating the reliability of MultiGlycan-ESI in quantitation of permethylated glycans analyzed by LC/MS. Automated quantitation resulted in a linear relationship for all six N-glycans derived from 50 ng to 400 ng fetuin with correlation coefficients (R(2) ) greater than 0.93. Spiking of permethylated fetuin N-glycans at different concentrations in permethylated N-glycan samples derived from a 0.02 μL of HBS also exhibited linear agreement with R(2) values greater than 0.9.
  
  
  CONCLUSIONS
  With a variety of options, including mass accuracy, merged adducts, and filtering criteria, MultiGlycan-ESI allows automated annotation and quantitation of LC/ESI-MS N-glycan data. The software allows the reliable quantitation of glycan LC/MS data. The software is reliable for automated glycan quantitation, thus facilitating rapid and reliable high-throughput glycomics studies.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX, 79409, USA.
authors.forename: Yunli
authors.initials: Y
authors.lastname: Hu
authors.forename: Shiyue
authors.initials: S
authors.lastname: Zhou
authors.forename: Chuan-Yih
authors.initials: CY
authors.lastname: Yu
authors.forename: Haixu
authors.initials: H
authors.lastname: Tang
authors.forename: Yehia
authors.initials: Y
authors.lastname: Mechref
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D066289:Data Curation; D006023:Glycoproteins / Q000097:blood; D006801:Humans; D016014:Linear Models; D008956:Models, Chemical; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry*; D012984:Software; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D006023:Glycoproteins; D011134:Polysaccharides