Identification and characterization of the antigenic site (epitope) on bovine β-lactoglobulin: common residues in linear and conformational epitopes

Abstract

Background: β-Lactoglobulin is recognised as one of major allergens in milk and its epitopes include linear and conformational epitopes contributed to milk allergy.

Results: In our work, two types of epitopes have been identified. Linear epitopes identified by using SPOT™ peptide arrays approach and three common peptide sequences AA77-82 (KIPAVF), AA126-131 (PEVDNE) and AA142-147 (ALPMHI) were obtained by reacting with specific sera from two rabbits. At the same time, mimotopes were screened by the panning of a phage display peptide library and the corresponding conformational epitopes were calculated by the web tool of Peptiope server with Mapitope algorithm. Three conformational epitopes against two specific sera were identified, in which there were 15 common residues as well and located in the different position and appeared mainly as an α-helix.

Conclusion: Common residues on the linear and conformational epitopes were identified in the first time, respectively, which could be regarded as informative epitopes for detection of allergen in dairy products.

Keywords: allergen; bovine β-lactoglobulin; common residues; epitope.