TY - JOUR
T1 - Structural Analysis of Sulfated Glycans by Sequential Double-Permethylation Using Methyl Iodide and Deuteromethyl Iodide
AU - Lei, Ming
AU - Mechref, Yehia
AU - Novotny, Milos V.
N1 - Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.
PY - 2009/9
Y1 - 2009/9
N2 - MALDI mass spectrometric characterization of sulfated glycans is often challenging due to their low ionization response in the positive ion mode. Here we demonstrate a new analytical approach, allowing the measurement of sulfated glycans by substituting the sulfate group with a deuteromethyl group. Sulfated glycan samples are initially permethylated before the methanolytic cleavage of their sulfate groups. Desulfated and permethylated glycans are then subjected to another permethylation step using deuteromethyl iodide to label the hydroxyl groups resulting from methanolysis. The number of attached sulfate groups is subsequently calculated from the mass-shift resulting from the chemical cleavage of these sulfate groups. The position of the sulfate substitution is then determined by collision-induced dissociation (CID) tandem mass spectrometry of permethylated and permethylated plus deuteromethylated samples. The described approach was initially optimized and validated using linear standard glycans, while its effectiveness has also been demonstrated here for the N-glycans derived from bovine thyroid-stimulating hormone (bTSH).
AB - MALDI mass spectrometric characterization of sulfated glycans is often challenging due to their low ionization response in the positive ion mode. Here we demonstrate a new analytical approach, allowing the measurement of sulfated glycans by substituting the sulfate group with a deuteromethyl group. Sulfated glycan samples are initially permethylated before the methanolytic cleavage of their sulfate groups. Desulfated and permethylated glycans are then subjected to another permethylation step using deuteromethyl iodide to label the hydroxyl groups resulting from methanolysis. The number of attached sulfate groups is subsequently calculated from the mass-shift resulting from the chemical cleavage of these sulfate groups. The position of the sulfate substitution is then determined by collision-induced dissociation (CID) tandem mass spectrometry of permethylated and permethylated plus deuteromethylated samples. The described approach was initially optimized and validated using linear standard glycans, while its effectiveness has also been demonstrated here for the N-glycans derived from bovine thyroid-stimulating hormone (bTSH).
UR - http://www.scopus.com/inward/record.url?scp=69549088131&partnerID=8YFLogxK
U2 - 10.1016/j.jasms.2009.05.001
DO - 10.1016/j.jasms.2009.05.001
M3 - Article
C2 - 19546010
AN - SCOPUS:69549088131
VL - 20
SP - 1660
EP - 1671
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
SN - 1044-0305
IS - 9
ER -