Why Protein Modifications Matter for Digestibility: The Case of Ara h 1 Peanut Allergen and Trypsin Cleavage.

Trypsin is the principal intestinal endopeptidase and proteomics digestion tool, yet the impact of protein modifications (PMs) on digestibility and allergenicity remains underexplored. We employed a proteomic approach to assess trypsin cleavage efficacy (TCE) at modified versus unmodified K/R residues in Ara h 1, a major peanut allergen. Seven of 17 PM sites showed ≥20% difference in TCE, with carbamoylation + methylation and dihydroxylation retaining significance after multiple-testing correction.