Altered glycosylation of alpha1-acid glycoprotein in patients with inflammation and diabetes mellitus.
BACKGROUND
In certain pathophysiological conditions, such as inflammation rheumatoid arthritis and diabetes mellitus (DM), alterations in asparagine-linked glycan (N-glycan) patterns of the acute-phase protein, alpha(1)-acid glycoprotein (AGP), have been reported. In this study, we investigated N-glycan structures of AGP purified from the sera of patients with acute inflammation (n=5), type 2 diabetes mellitus (n=5), and healthy individuals (n=5).


METHODS
N-Glycans were released with peptide N-glycosidase F (PNGase F) from denatured AGP and purified with cellulose cartridge. N-glycans were analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOFMS) in combination with exoglycosidase digestion.


RESULTS
We revealed increases in bi-antennary complex glycans and in alpha1-3 fucosylated bi-, tri-, and tetra-antennary glycans and a decrease in tri-antennary glycans in inflammation patients. These results support increases in bindings to concanavalin A (ConA) and Aleuria aurantia lectins (AALs). In diabetic patients, the pathogenesis-specific change in N-glycan patterns of AGP was not significant.


CONCLUSIONS
The MALDI-TOFMS method is sensitive and suitable for profiling analysis of N-glycans in clinical samples.
Higai
Koji
K
Department of Clinical Chemistry, School of Pharmaceutical Sciences, Toho University, Funabashi, Chiba, Japan. koji@phar.toho-u.ac.jp
Azuma
Yutaro
Y
Aoki
Yutaka
Y
Matsumoto
Kojiro
K
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000737:chemistry; D006031:Glycosylation; D006041:Goats / Q000276:immunology; D006801:Humans; D006868:Hydrolysis; D007249:Inflammation / Q000150:complications / Q000378:metabolism*; D009961:Orosomucoid / Q000302:isolation & purification / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000378:metabolism; D012794:Sialic Acids / Q000737:chemistry / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D009961:Orosomucoid; D011134:Polysaccharides; D012794:Sialic Acids; D006026:Glycoside Hydrolases