Structural Analysis of the Sugar Chains of Human Urinary Thrombomodulin

抄録

The sugar chains of human urinary thrombomodulin were studied. N- and O-linked sugar chains were simultaneously liberated by hydrazinolysis followed by N-acetylation and were tagged with 2-aminopyridine. Then the structures of the N- and O-linked pyridylamino (PA-) sugar chains were analyzed by two-dimensional sugar mapping combined with exoglycosidase digestion. The major N-linked sugar chains of human urinary thrombomodulin were found to be monosialo- and disialofucosylbiantennary chains, while the major Olinked sugar chain was ±Siaα2-3Galβ1-3 (±Siaα2-6)GalNAc. Thrombomodulin also contained the reported structure SO₄-3GlcAβ1-3Galβ1-3(±Siaα2-6)Galβ1-4Xyl [H. Wakabayashi, S. Natsuka, T. Mega, N. Otsuki, M. Isaji, M. Naotsuka, S. Koyama, T. Kanamori, K. Sakai, and S. Hase (1999) J. Biol. Chem. 274, 5436-5442]. In addition to these sugar chains, a single Glc was linked to Ser 287.