STRUCTURAL DETERMINATION OF 2 N-LINKED GLYCANS ISOLATED FROM RECOMBINANT HUMAN LACTOFERRIN EXPRESSED IN BHK CELLS

A full-length cDNA coding for human lactoferrin was isolated from a ma mmary gland library and the recombinant protein was expressed in BHK c ells as described by Stowell K.M. et al, [1998, Biochem. J. 276, 349-3 55]. Two N-linked glycans from purified recombinant lactoferrin were r eleased by hydrazinolysis and analyzed by 400-MHz H-1-NMR spectroscopy . The identified structures corresponded to N-acetyllactosaminic biant ennary glycans and were alpha-2,3-disialylated forms (80%) or alpha-2, 3-monosialylated (20%) forms. Moreover, 70% of total glycans were alph a-1,6-fucosylated at the GlcNAc residue linked to asparagine, In regar d to its glycan moiety, the recombinant glycoprotein is close to nativ e lactoferrins from milk or leucocytes but shows specific structural f eatures which should be taken into account prior to in vivo and in vit ro biological studies.