Figure 3.

Effect of cysteine S-ascorbylation on IgE binding to Mal d 1: (A) IgE reactivity to the plate-bound isoform Mal d 1.0101, as measured by ELISA using blood sera of 10 birch pollen- and apple-allergic patients. Data are shown for recombinantly produced allergen before (dark blue) and after incubation with oxidized L-ascorbate (light blue). Identical amounts of allergen were used in all experiments. Depending on the available sera, either one or two experiments in triplicates were performed (see Tables S1 and S2). Average OD values are shown. Error bars represent standard deviations. (B) ELISA data for the isoform Mal d 1.0201, which lacks surface-exposed cysteine residues, before (dark green) and after incubation with L-ascorbate (light green). (C) Individual, patient-specific trends illustrate changes in IgE reactivities upon S-ascorbylation in the isoform Mal d 1.0101.