Fig. 1.

NCBI-derived Mal d proteins and their isoforms. Phylogenetic analysis of Mal d proteins (refer to Material and Methods). Mal d group numbers are displayed in the outermost circle. Isoforms identified by at least one isoform-specific peptide are indicated in bold. Isoforms detected by unspecific peptides are highlighted with white dashed lines (a). Frequency of specific peptides for the corresponding allergens (b). Peptide length distribution (c). Peptide position within Mal d1 protein sequences (d).