Preparation and Identification of Per a 5 as a Novel American Cockroach Allergen
Figure 3
Expression and purification of Per a 5 in E. coli. (a) Per a 5 was induced by 0.1, 0.5, and 1 mM IPTG, respectively, and was analyzed by SDS-PAGE. Lane M: Smart Broad-Range Protein Standard (Genscript, Nanjing, China); lanes 1, 2, 3, and 4 represent lysates of cells induced with 0.5, 0.1, 1.0, or 0 mM IPTG, respectively. The arrow indicates Per a 5 protein. (b) SDS-PAGE analysis of purified Per a 5 expressed in E. coli. Lane M: protein standard; lane 1: the supernatant of cells lysate after centrifugation; lane 2: run through; lane 3: wash with 50 mM imidazole; lane 4: wash with 250 mM imidazole. The arrow indicates recombinant Per a 5 protein.
