Quantitative detection of Ganodermati lucidum immunomodulatory protein-8 by a peptide-antigen-antibody sandwich ELISA

In order to rapidly determine the concentration of recombinant Ganoderma lucidum immunomodulatory protein-8 (rLZ-8) at a lower cost, a peptide–antigen–antibody sandwich ELISA method was developed based on a dodecapeptide LTPHKHHKHLHA with higher affinity for rLZ-8, which was identified from phage display after four rounds of screening. The binding mode between rLZ-8 and the peptide ligand was further simulated and revealed by molecular docking. Standard addition and repetitive testing were carried out to evaluate the accuracy, reproducibility and feasibility of the developed ELISA detection method. The method based on this peptide ligand was then successfully applied in the quantitative determination of rLZ-8 concentrations in fermentation broth. In summary, the peptide–antigen–antibody sandwich ELISA method developed here could be conveniently applied in the detection of rLZ-8 during fermentation and might provide new insights for the detection of other specific proteins.