title: Use of cloneable peptide-MBP fusion protein as a mimetic coating antigen in the standardized immunoassay for mycotoxin ochratoxin A.
abstract: The quality of mycotoxin conjugates is essential to the development of reliability of immunoassays for mycotoxins. However, conventional mycotoxin conjugates are usually synthesized by chemical methods, which are harmful to the environment and yield unwanted cross-reactions. In this study, using ochratoxin A (OTA) as a model system, a selected OTA mimotope (phage-displayed peptide) that specifically binds to anti-OTA antibody was expressed as soluble and monovalent fusions to maltose binding protein (MBP). These prepared fusion proteins can serve as a mimetic coating antigen in both a quantitative chemiluminescent enzyme-linked immunoassay (CLEIA) and a qualitative dot immunoassay for OTA. One of the prepared mimetic coating antigen (L12-206-MBP)-based CLEIAs exhibited a half-inhibition concentration (IC50) of 0.82 ng/mL and a working range of 0.30-2.17 ng/mL, which resemble those of the conventional OTA-OVA conjugate-based immunoassay. The dot immunoassay developed with both the OTA-OVA conjugate and the mimetics showed identical visual cutoff values of 5 ng/mL. The mimetic coating antigen proposed here is an OTA-free product and can be prepared reproducibly as a homogeneous product and facilitates standardization of immunoassays for the mycotoxin OTA.
authors.affiliation: State Key Laboratory of Food Science and Technology, Sino-Germany Joint Research Institute, Nanchang University , No. 235 Nanjing East Road, Nanchang 330047, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xu
authors.forename: Zhenyun
authors.initials: Z
authors.lastname: He
authors.forename: Qinghua
authors.initials: Q
authors.lastname: He
authors.forename: Yulou
authors.initials: Y
authors.lastname: Qiu
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
authors.forename: Xing
authors.initials: X
authors.lastname: Liu
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000295:instrumentation / Q000379:methods; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D058619:Maltose-Binding Proteins / Q000235:genetics / Q000378:metabolism; D009183:Mycotoxins / Q000032:analysis*; D009793:Ochratoxins / Q000032:analysis*; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D058619:Maltose-Binding Proteins; D009183:Mycotoxins; D009793:Ochratoxins; D010455:Peptides; C025589:ochratoxin A