Filamin C is an allergen of Scylla paramamosain (Scy p 9), and six IgE linear epitopes of the allergenic predominant
region had previously been validated. However, the IgE epitope and
structure–allergenicity relationship of Scy p 9 are unclear.
In this study, a hydrophobic bond was found to be an important factor
of conformation maintaining. The critical amino acids in the six predicted
conformational epitopes were mutated, and the IgE-binding capacity
and surface hydrophobicity of four mutants (E216A, T270A, Y699A, and V704A) were reduced
compared to Scy p 9. Ten linear epitopes were verified with synthetic
peptides, among which L-AA187–205 had the strongest
IgE-binding capacity. In addition, IgE epitopes were mapped in the
protruding surface of the tertiary structure, which were conducive
to binding with IgE and exhibited high conservation among filamin
genes. Overall, these data provided a basis for IgE epitope mapping
and structure–allergenicity relationship of Scy p 9.