Figure 2. Prediction accuracy using individual and combined lectins.

A) Motif prediction scores for terminal, alpha-GlcNAc. Using only GSL-2 (top left) and only HAA (top right), we calculated the motif prediction score for every glycan on the array for the terminal, alpha-GlcNAc motif and plotted the scores for the glycans without the motif (n = 602) and the glycans with the motif (n = 9). Both lectins had high scores for some glycans that did not have terminal, alpha-GlcNAc. When we calculated the motif prediction scores using both lectins (bottom, calculated by adding the scores from the two lectins for each glycan), all the glycans with the motif had higher scores that all the glycans without the motif. The size of each circle indicates the number of glycans with values in the region. We chose the thresholds to give maximum in discriminating between the groups. B) Motif prediction scores for distinct sets of glycans. We separately analyzed glycans that contained terminal beta-GlcNAc (left), terminal alpha-GalNAc (middle), or terminal alpha-GlcNAc. For each glycan, we calculated the motif prediction score for the terminal alpha-GlcNAc motif using either HAA alone, GSL-2 alone, or both HAA and GSL-2. Ideally, only glycans containing terminal alpha-GlcNAc (the glycans in the right box) should have high scores. GSL-2 but not HAA reacts with glycans containing terminal beta-GlcNAc; HAA but not GSL-2 reacts with glycans containing terminal alpha-GalNAc; and both lectins react with glycans containing the targeted motif of terminal alpha-GlcNAc. Therefore, the glycans with the targeted motif can be differentiated from the other glycans using the combined motif prediction score.