Carbohydrate-targeted optimization of therapeutic gonadotropins - Carbohydrate Chemistry: Chemical and Biological Approaches - page 469

Fig. 3 Worldwide demand of therapeutic gonadotropins over the past decade (adapted
from Ref 1).
Fig. 4 Glycan structures present on recombinant human FSH (determined from
Amoresano et al., 1996, 25 Recombinant Human FSH Product Development Group, 1998, 70
and Gervais et al., 2003 71 ).
fucosylated complex bi-, tri-, tetra- and pentaantennary glycans. Bian-
tennary glycans are the most represented (Fig. 4). 25,70,71 rFSH glycoforms
show less complex 72 as well as less acidic forms than highly purified
urinary Metrodin-HP s (glycoforms with pI o 3.5: 12.4% vs 50.2%). 28
Comparison of the monosaccharide compositions of recombinant hFSH
showed that the product are less sialylated than urinary or pituitary FSH
(2.2 sialic acids per glycan vs. 2.8-2.9 sialic acids per glycan), indicating a
need for further improvement for second generation product. 70
4.2 LH
Mass spectrometry analysis showed that rhLH contains bi- and trian-
tennary N-glycans more or less sialylated and fucosylated. None of them
contains GalNAc sulfate. Whereas fucosylated glycans are absent on the
a-subunit, they are highly represented on the b-subunit. While trian-
tennary oligosaccharides constitute only minor components in rFSH,
they are as abundant as the biantennary structures in rhLH. 25,71 Minor
trisialylated tetraantennary glycans as well as fucosylated or not mono-
and disialylated pentaantennary glycans were also detected (Fig. 5). 71