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Characterization of oligosaccharide moieties of intact glycoproteins by microwave‐assisted partial acid hydrolysis and mass spectrometry
Author(s) -
Lee BaoShiang,
Krishnanchettiar Sangeeth,
Lateef Syed Salman,
Lateef Nabila Salman,
Gupta Shalini
Publication year - 2005
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.2096
Subject(s) - chemistry , glycoprotein , fetuin , oligosaccharide , mass spectrometry , chromatography , ribonuclease , biochemistry , avidin , sialic acid , hydrolysis , glycosylation , biotinylation , rna , gene
Abstract A method, which utilizes microwave‐assisted partial acid hydrolysis and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS), to elucidate oligosaccharide composition of intact glycoproteins is presented here. Glycoproteins, such as ribonuclease B, avidin, α 1 ‐acid glycoprotein, and fetuin, are used as model systems to demonstrate this technique. Partial cleavage of oligosaccharides from whole intact glycoproteins with trifluoroacetic acid was observed after a short exposure to microwaves. Due to the high‐resolution mass spectra obtained by MALDI‐TOFMS from glycoproteins with molecular weights less than 20 kDa, the compositions of oligosaccharides are readily derived for ribonuclease B and avidin. The data agree with the proposed oligosaccharide structures of ribonuclease B (five glycoforms) and avidin (eight glycoforms). Larger glycoproteins such as α 1 ‐acid glycoprotein (many glycoforms) and fetuin (many glycoforms) exhibited only broad peaks with no glycoform resolution. Nevertheless, this method can be used successfully for analysis of glycoproteins with molecular weights greater than 20 kDa to determine the presence or absence of glycosylation. Copyright © 2005 John Wiley & Sons, Ltd.