title: Development of an indirect competitive immunoassay for walnut protein component in food.
abstract: Among food allergens, walnut is a frequent cause of adverse food reactions in allergic patients. In this study, the walnut allergen protein 2S albumin precursor (Jug r 1) cDNA was synthesised and cloned into the pGEX-6P-1 expression vector. The recombinant plasmids were transformed into Escherichia coli (E. coli) BL21(DE3) pLys for expression of protein Jug r 1. Polyclonal antibodies were prepared against the expressed purified Jug r 1 protein. An indirect competitive enzyme-linked immunosorbent assay (ELISA) for the detection and quantification of walnut soluble proteins in processed foods was developed using the prepared polyclonal antibodies. The developed ELISA had a high specificity, walnut protein standard solution at 2.2 ng/mL [inhibition concentration (IC80) of the competitive test] was clearly identified by the ELISA. The mean recoveries ranged from 86% to 112%. The coefficient of variation (CV) for the 4 model foods was 6.4-8.7%.
authors.affiliation: Institute of Food Safety, Chinese Academy of Inspection and Quarantine, No. 3, Gaobeidian North Road, Chaoyang District, Beijing 100123, PR China; Inner Mongolia Entry-Exit Inspection and Quarantine Bureau, No. 12, Erdos Street, Huhhot, Inner Mongolia 010020, PR China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Li
authors.forename: Yajun
authors.initials: Y
authors.lastname: Wu
authors.forename: Fei
authors.initials: F
authors.lastname: Yuan
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
mesh_terms: D052179:Antigens, Plant / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005504:Food Analysis; D005512:Food Hypersensitivity / Q000517:prevention & control; D006801:Humans; D031324:Juglans / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D010940:Plant Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology
chemical_list: D052179:Antigens, Plant; D010940:Plant Proteins
keywords: Allergen; ELISA; Indirect competitive; Walnut