Inflammation-induced expression of sialyl LewisX is not restricted to alpha1-acid glycoprotein but also occurs to a lesser extent on alpha1-antichymotrypsin and haptoglobin.
Acute and chronic inflammation-induced expression of sialyl LewisX has already been shown to occur on alpha1-acid glycoprotein. We now demonstrate that this phenomenon is not restricted to alpha1-acid glycoprotein but also occurs on two other acute-phase proteins. ie on alpha1-antichymotrypsin and on haptoglobin. The level of expression of sialyl LewisX on these proteins was lower than on alpha1-acid glycoprotein, in all likelihood because alpha1-acid glycoprotein is the only acute-phase protein containing tetraantennary glycans. No expression of sialyl LewisX was detectable on alpha1-protease inhibitor, a protein with a high diantennary glycan content. Non-sialylated LewisX was not detectable on these major acute-phase proteins in any of the conditions studied. This indicates that the majority of the a3-linked fucose residues are present as sialyl LewisX on alpha1-acid glycoprotein, alpha1-antichymotrypsin and haptoglobin. The absolute contribution to the total phenotype in plasma of protein containing this determinant in a multivalent form was highest for alpha1-acid glycoprotein. This leads us to propose that alpha1-acid glycoprotein is, among the acute-phase proteins studied, the one with the highest potential for interference with the extravasation of leukocytes by binding to the selectins.
Brinkman-van der Linden
E C
EC
Department of Medical Chemistry, Faculty of Medicine, Vrije Universiteit, Amsterdam, The Netherlands.
de Haan
P F
PF
Havenaar
E C
EC
van Dijk
W
W
D000209:Acute-Phase Proteins / Q000032:analysis / Q000378:metabolism; D000911:Antibodies, Monoclonal; D001172:Arthritis, Rheumatoid / Q000378:metabolism; D015153:Blotting, Western; D003208:Concanavalin A; D004586:Electrophoresis / Q000379:methods; D006242:Haptoglobins / Q000378:metabolism*; D006801:Humans; D007249:Inflammation / Q000378:metabolism*; D037102:Lectins; D008099:Liver / Q000503:physiopathology; D009844:Oligosaccharides / Q000276:immunology / Q000378:metabolism*; D009961:Orosomucoid / Q000378:metabolism*; D000080506:Sialyl Lewis X Antigen; D014947:Wounds and Injuries / Q000378:metabolism; D000514:alpha 1-Antichymotrypsin / Q000378:metabolism*; D000515:alpha 1-Antitrypsin / Q000378:metabolism
D000209:Acute-Phase Proteins; D000911:Antibodies, Monoclonal; D006242:Haptoglobins; D037102:Lectins; D009844:Oligosaccharides; D009961:Orosomucoid; D000080506:Sialyl Lewis X Antigen; D000514:alpha 1-Antichymotrypsin; D000515:alpha 1-Antitrypsin; C064549:lectin, Aleuria aurantia; D003208:Concanavalin A