FIGURE 4.

Determination of the structural requirements at the nonreducing ends of the polyarabinose chain for recognition by poly-Araf–dependent mAbs by ELISA titrations. (A) Analysis of the importance of the Ara-α(1→5)–Ara linkage at the nonreducing sugar located at the branching point in the arabinose chain for Ab recognition by titration of the binding reactivities of the three Ara4-reactive mAbs shown. (B) Analysis of the requirement for the Ara-β(1→2)-Ara linkage at the terminal nonreducing position of the Ara4/Ara6 sequence by titration of the four mAbs indicated. (C) Analysis of the effects of capping and extensions at the nonreducing ends of the Ara6 structure on binding reactivity of the five mAbs shown. Results are presented as the percentage of maximum binding signal, rather than OD, to control for the various activities of the different secondary Abs (anti-mouse versus anti-human) used in these assays.