A novel strategy for designing the antioxidant and adhesive bifunctional protein using the Lactobacillus strain-derived LPxTG motif structure

Cell wall-anchored LPxTG proteins derived from the Lactobacillus are recognized to have excellent adhesion and gastrointestinal tolerance functions. Since the motif of LPxTG can interact with sortase A (SrtA) on the surface of Lactobacillus, it has great potential for various biotechnological applications. In this study, a bifunctional protein named LPxT-GYLEQ was designed by replacing the C-terminal hydrophobic domain with a synthetic antioxidant peptide containing an N-terminal glycine. It was found that the synthetic LPxT-GYLEQ protein exhibited better antioxidant activity in the H2O2-damaged HepG2 cells model. Meanwhile, it found that LPxT-GYLEQ protein can also exhibit good gastrointestinal tolerance function when pretreated with gastric juice and intestinal juice, and the DPPH radical scavenging ability of the LPxT-GYLEQ protein was increased by 12.8 % and 13.7 %, respectively, compared to the synthetic GYLEQ peptide. Further results also proved the good adhesion property of this synthetic protein (50 mu g/mL) in the intestinal cell model. The novel strategy design of the antioxidative and adhesive bifunctional protein with the LPxTG motif structure offers a new idea for the protection of antioxidant peptides in the host oral delivery system.

Automated summary

In this study, a bifunctional protein named LPxT-GYLEQ was developed by replacing the C-terminal hydrophobic domain with a synthetic antioxidant peptide. The LPxT-GYLEQ protein showed enhanced antioxidant activity in H2O2-damaged HepG2 cells and exhibited good gastrointestinal tolerance function. The protein also demonstrated strong adhesion in an intestinal cell model, offering a novel strategy for the protection of antioxidant peptides in oral delivery systems.