Abstract: Peanut is one of the most common and important food allergens. In this paper, peanut oil was degreased by petroleum ether and purified by ammonium sulfate salting out, dialysis and Sephadex G-150 dextran gel column. The molecular weight of peanut protein was determined by SDS-PAGE gel electrophoresis: 15, 20, 35 and 60 ku. Western-Blotting immunoblot test showed that peanut allergy was around 63.5 ku. 31 effective protein peptides were obtained by mass spectrometry sequencing. Among them, 5 peptides had higher number of spectra, namely, KLEYDPRCVYDTGAT, AFNAEFNEIRRVLLEE, DNVIDQIEKQAK, PYSPSQDPDRRDPY and QDPYSPSQDPDR, which accounted for 49.6% of the total number of spectra. Based on this, it is inferred that those peptides are the main peptide allergic sequences of peanut sensitizing proteins Ara h 1 and Ara h 2. The protein peptides are successfully used to infer the corresponding protein types, which lays a foundation for further clarifying the sensitization mechanism of peanut allergens. Since the conformational structure of peanut allergic protein is complex, further research work needs to be carried out by other means

Key words: peanut, allergic protein, separation and purification, protein peptide