title: Expression, purification, and characterization of almond (Prunus dulcis) allergen Pru du 4.
abstract: Biochemical characterizations of food allergens are required for understanding the allergenicity of food allergens. Such studies require a relatively large amount of highly purified allergens. The level of Pru du 4 in almond is low, and its expression in a soluble form in Escherichia coli required an expression tag. An MBP tag was used to enhance its expression and solubility. Sumo was used for the first time as a peptidase recognition site. The expression tag was removed with a sumo protease, and the resulting wild-type Pru du 4 was purified chromatographically. The stability of the allergen was investigated with chemical denaturation. The Gibbs free energy of Pru du 4 folding-unfolding transition was determined to be 5.4 ± 0.7 kcal/mol.
authors.affiliation: U.S. Department of Agriculture, Agricultural Research Service, Pacific West Area, Western Regional Research Center, 800 Buchanan Street, Albany, California 94710, United States.
authors.forename: Yuzhu
authors.initials: Y
authors.lastname: Zhang
authors.forename: Wen-Xian
authors.initials: WX
authors.lastname: Du
authors.forename: Cécile
authors.initials: C
authors.lastname: Fregevu
authors.forename: Mahendra H
authors.initials: MH
authors.lastname: Kothary
authors.forename: Leslie
authors.initials: L
authors.lastname: Harden
authors.forename: Tara H
authors.initials: TH
authors.lastname: McHugh
mesh_terms: D052179:Antigens, Plant / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D017510:Protein Folding; D027861:Prunus / Q000737:chemistry* / Q000235:genetics / Q000276:immunology
chemical_list: D052179:Antigens, Plant; D010940:Plant Proteins
keywords: allergen; almond; food allergy; stability; sumo; tree nut allergy