Expression of N-linked sialyl Le(x) determinants and O-glycans in the carbohydrate moiety of human amniotic fluid transferrin during pregnancy.
Transferrin, a glycoprotein involved in iron transport in body fluids, was isolated from amniotic fluid of a hydramniospatient by sequential anion-exchange chromatography and gel filtration. The N-glycans of human amniotic fluid transferrin (hAFT) were enzymatically liberated by PNGase-F digestion, isolated by gel filtration and fractionated by (high-pH) anion-exchange chromatography. After alkaline borohydride treatment of native hAFT, the released O-glycans were isolated by gel filtration and fractionated by anion-exchange chroma-tography. Structure elucidation of 14 N- and 2 O-glycans was performed by 500 or 600 MHz1H-NMR spectroscopy. Besides conventional N-glycans established earlier for human serum transferrin (hST), new (alpha1-3)-fucosylated N-glycans were found, representing sialyl Le(x) elements. Furthermore, as compared to hST, a higher degree of (alpha1-6)-fucosylation and an increase in branching from di- to triantennary compounds has been detected. The presence of O-glycans is demonstrated for the first time in transferrin.
van Rooijen
J J
JJ
Bijvoet Center, Department of Bio-Organic Chemistry, Utrecht University, P.O. Box 80075, NL-3508 TB Utrecht, The Netherlands, Universität Rostock, Frauenklinik, P.O. Box 18055, Rostock, Germany.
Jeschke
U
U
Kamerling
J P
JP
Vliegenthart
J F
JF
D000596:Amino Acids / Q000032:analysis; D000653:Amniotic Fluid / Q000737:chemistry*; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D005260:Female; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000032:analysis / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000032:analysis* / Q000737:chemistry; D006831:Polyhydramnios / Q000097:blood / Q000378:metabolism; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry; D011247:Pregnancy; D000080506:Sialyl Lewis X Antigen; D014168:Transferrin / Q000737:chemistry*
D000596:Amino Acids; D007983:Lewis Blood Group Antigens; D009844:Oligosaccharides; D011134:Polysaccharides; D000080506:Sialyl Lewis X Antigen; D014168:Transferrin