Table 1.
HS epitopes recognized by phage display-derived antibodies
| Antibody | Modifications involved in binding |
|---|---|
| HS4C3a | N-sulfation (essential)d |
| 6-O-sulfation (essential)d | |
| 3-O-sulfation (essential)d | |
| 2-O-sulfationd | |
| HS4E4b,c | N-sulfation |
| N-acetylation | |
| Iduronate | |
| Unspecified O-sulfated epitopes required? | |
| High 2- and 6-O-sulfation reduce binding | |
| AO4B08b | N-sulfation |
| Iduronate | |
| Internal 2-O-sulfatione | |
| High 6-O-sulfatione | |
| RB4Ea12c | N-acetylation |
| N-sulfation | |
| 6-O-sulfation | |
| EV3C3c | Unknown |
| MPB49c | Not reactive with HS |
a
Data from ten Dam et al. (2006).
b
Data from Kurup et al. (2007).
c
Data from Wijnhoven et al. (2008).
d
Antibody HS4C3 was shown to recognize the antithrombin-binding minimal pentasaccharide GlcNAc/S–GlcA–GlcNAc/NS3,6diS–IdoA2S–GlcNS,6S, as well as other 3-O-sulfated motifs.
e
Antibody AO4B08 requires an internal 2-O-sulfated iduronic acid residue and more than one 6-O-sulfate within a target octasaccharide.
Epitopes are not sequentially defined but involve the presence of various structural features in the target oligosaccharide, while other features may be inhibitory to reactivity. HS, heparan sulfate.