Isolation,Purification And Identification Of Major Allergens Of Chinese Bayberry

For most people, fruit is a healthy food, but there are some people who are allergic to one or more fruits, because of their own genetic predisposition and living environment. The phenomenon is becoming more common with the dramatic increasing of fruit production and consumption due to fruit production specialization and sales network worldwide. Fruit allergy is generally referred to type Ⅰ hypersensitivity, an overreaction of the immune system in patients to some proteins.This type of disease affects approximately1-3%people among the world. Therefore, research on fruit allergens can protect people’s life and play an important role on improving people’s quality of life. Moreover, it also has a great economic and social benefit. Here we choose Chinese bayberry (Myrica rubra), a common fruit in southern China as the research material, focusing on the separation and purification of allergen protein from Chinese bayberry fruit as well as analysis of immunologic property.First of all, protein from Chinese bayberry was extracted using Coca’s method. SDS-PAGE was applied to separate total protein from the Chinese bayberry extract, SDS-PAGE spectrum showed Chinese bayberry protein extracts contained the major allergen protein, the same as the protein band with the molecular weight about28kDa.Secondly, the Chinese bayberry allergen proteins were purified by Ultrafiltration centrifugation, SP-FF ion exchange chromatography and Superdex7510/300GL gel column chromatography. According to the amino acid data derived from Chinese bayberry transcriptome and then the Chinese bayberry allergen protein was analyzed through peptide fingerprinting, molecular mass spectrometry and ELISA methods. The result showed the observed molecular mass weight was in agreement with theoretical molecular mass weight of Chinese bayberry allergen protein deduced from expressed sequences and it had specific IgE binding capacity. Peptide fingerprinting assay and sequence alignment indicated the Chinese bayberry allergen protein belonged to Class Ⅲ of the chitinase family and its encoding sequence has been deposited to NCBI data base (accession number:KP307670).In summary, the Chinese bayberry allergen proteinhas been firstly purified, characterized and identified. It will be used as a base for further study on structure and function of Chinese bayberry allergens. As a specific antigen tested by ELISA, it has a good reaction to the specific IgE from patientswho are allergic to the Chinese bayberry. It will also be used as a base for the specific diagnosis and immunotherapy in Chinese bayberry hypersensitivity disease.