Figure 3 - Data mining analysis of HA binding glycan array data.

(a) Examples of the types of glycan features (e.g., pairs, triplets and quadruplets) abstracted from a representative complex glycan structure. A comprehensive set of these features was abstracted from the glycans in the glycan array. (b) Graphical representations of the complex classifier rules (Supplementary Table 1) for each HA analyzed using the glycan array. The 2-3 Type A represents broadest specificity, whereas the Type B and Type C classifiers represent constraints imposed by structural variations around the trisaccharide 2-3 motif. The 2-6 Type A represents binding to long 2-6, whereas Type B represents binding to short 2-6 (linear or branched). The core corresponds to either the spacer attached to the reducing end or the trimannosyl core in case of the single 2-6 biantennary glycan on the array. ^aBinding signals observed for fucosylated 2-3 motif only if it has GlcNAc[6S]. ^bBinding signals observed only for 6'-sialyl lactose. ^cBinding signals also observed for short 6'-sialyl lactosamine (Type B). ^dBinding signals are significantly lower than 2-3 Type B of H5N1 double mutant. ^eBinding signals observed only for short 2-6 with GlcNAc[6S]. ^fBinding signals just above background observed for 2-3 motif with GlcNAc[6S]. ^*The origin of A/Vietnam/1203/04 is avian but this viral strain was isolated from an infected human.