Scope:
There are differences in stability to pepsin between the major allergens in peanut; however, data are from different reports using different digestion models. this study provides a comprehensive comparison of the digestibility of the major peanut allergens.
Methods and results:
Peanut allergens ara h 1, ara h 2, ara h 3 and ara h 6 were incubated with pepsin to mimic the effect of gastric digestion. samples were analyzed using sds-page. to further investigate resistance to digestion, ara h 2 was additionally subjected to digestion with trypsin and residual peptides were characterized. ara h 1 and ara h 3 were rapidly hydrolyzed by pepsin. on the contrary, ara h 2 and ara h 6 were resistant to pepsin digestion, even at very high concentrations of pepsin. in fact, limited proteolysis could only be demonstrated by sds-page performed under reducing conditions, indicating an important role for the disulfide bridges in maintaining the quaternary structure of ara h 2 and ara h 6. trypsin digestion of ara h 2 similarly resulted in large residual peptides and these were identified.
Conclusion:
Ara h 2 and ara h 6 are considerably more stable towards digestion than ara h 1 and ara h 3.