Application of Mimotope Peptides of Fumonisin B1 in Peptide ELISA

Abstract

Anti-fumonisin B₁ (FB₁) McAb 1D11 was used as the target for biopanning from a phage random loop-constrained heptapeptide library. After three cycles of panning, seven phages with three mimotope peptides were selected to mimic the binding of FB₁ to 1D11. After the identification of phage ELISA, the phage clone that showed the best linear range of detection was chosen for further research. One peptide with the inserted peptide sequence of the phage was synthetized, named CT-452. An indirect competitive ELISA (peptide ELISA) for detecting FB₁ was established using the CT-452-bovine serum albumin conjugate as coating antigen. The linear range of the inhibition curve was 1.77–20.73 ng/mL. The half inhibitory concentration (IC₅₀) was 6.06 ng/mL, and the limit of detection was 1.18 ng/mL. This method was compared with conventional indirect ELISA (commercial ELISA kit) and high-performance liquid chromatography (HPLC), and the results showed the reliability of the peptide ELISA for the determination of FB₁ in cereal samples. The relationship between the CT-452 and FB₁ standard concentrations in peptide ELISA was evaluated. The results indicated that synthetic peptide CT-452 can replace the FB₁ standard to establish an immunoassay free of FB₁.