| Abstract: 【Objective】The olecranon peach is known as one of the characteristic fruits in Lingnan region because
of its good flavor and quality, and it is listed as “The top ten best fruits in Lingnan”. However, less studies on its allergens
have been reported. By analyzing the epitope of allergen protein, it would provide a research basis for the preparation of the
recombinant antigen of the allergen, and also provide a research basis for explaining the characteristic changes and sensitization
characteristics of the allergen in the process of food processing.【Method】Phosphate buffer saline was used to extract the
crude protein from the lyophilized powder of olecranon peach, and the allergens in the crude protein were identified by SDSPAGE protein electrophoresis and analyzed by mass spectrometry. The allergens were screened and compared by the protein
database of UniProt, and the physicochemical properties, spatial structure and antigenic epitopes of the allergens were analyzed
by bioinformatics methods.【Result】Seven kinds of allergenic proteins including A0A251RBV3, P86888, M5X697, M5WV03,
M5WTQ8, Q2I6V8, and Q9LED1 were identified from olecranon peach, which belonged to the four classes of allergenic
proteins, namely, pathogenesis-related proteins (Pru p 1), thaumatin-like proteins (Pru p 2), non-specific lipid transfer proteins
(Pru p 3) and gibberellin-regulated proteins (Pru p 7). The seven kinds of allergenic proteins in olecranon peach had high
stability, their molecular weight is 6.91-26.04 kD, with the aliphatic index between 29.37 and 81.54. M5WTQ8 and Q2I6V8
allergen proteins were acidic proteins, while the remaining allergen proteins were alkaline proteins. Except for Q9LED1 protein,
all other allergen proteins were hydrophilic proteins. The regions with antigenic epitopes, hydrophilicity and flexibility greater
than 0 and surface accessibility greater than 1 were screened, and regions with low protein bonding energy were analyzed by
binding the secondary and tertiary structures of proteins to obtain the antigenic epitopes of allergens, including Pru p1 (EIP,
GSQ, KEN, NL, KG, EIK, HPD), Pru p 2 (TGDQKPQ, SP, NQ, PPNDKPETCPPT, DDKSS, RP), Pru p 3 (RT, VN) and Pru
p 7 (AGY, GTYGN, LKNSKGN).【Conclusion】By analyzing the structure, hydrophilicity, surface accessibility, flexibility
and antigen index of olecranon peach, multiple epitopes of 7 allergens are obtained, which can provide a research basis for the
sensitization characteristics of olecranon peach allergens in food processing. |
