The interaction of peptide inhibitors and Aβ protein: Binding mode analysis, inhibition of the formation of Aβ aggregates, and then exert neuroprotective effects

Yuchen Wu; Shuang Guo; Kunli Wang; Jingjing Kang

doi:10.3389/fnagi.2023.1139418

The interaction of peptide inhibitors and Aβ protein: Binding mode analysis, inhibition of the formation of Aβ aggregates, and then exert neuroprotective effects

Front Aging Neurosci. 2023 Apr 11:15:1139418. doi: 10.3389/fnagi.2023.1139418. eCollection 2023.

Authors

Yuchen Wu¹, Shuang Guo², Kunli Wang¹, Jingjing Kang¹

Affiliations

¹ College of Veterinary Medicine, Henan University of Animal Husbandry and Economy, Zhengzhou, China.
² College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China.

Abstract

Introduction: The misfolding and aggregation of β-amyloid (Aβ) easily form Aβ fibers, which are continuously deposited in the brain, leading to the massive generation of amyloid plaques, severely destroying neuronal connections, and promoting Alzheimer's disease (AD) The occurrence and development of AD is one of the pathogenesis of AD. There is an urgent need to develop inhibitors against Aβ aggregation, which is hopefully a potential way to treat AD.

Methods: In this study, we first found the crystal structure of the Aβ_1-42 receptor protein from the RCSB PDB protein structure database and used the SYBYL X2.0 software for molecular docking, and then used the Peptide Ranker, Innovagen, DPL, and ToxinPred online websites to perform peptides. Predict the activity score, toxicity and water solubility, and then calculate the affinity constant KD value of polypeptide and Aβ through Surface Plasmon Resonance (SPR) experiment. Subsequently, the CCK-8 kit method was used to determine the toxicity of different concentrations of peptides (3.125, 6.25, 12.5, 25, 50, 100, 200 μM) to PC12 cells, and then the peptides and Aβ according to different concentration ratios (1:4, 1:2, 1:1, 1:0.5, 1:0.25, 0:4), this method is also used to detect the effect of peptides on Aβ-induced neurotoxicity. The thioflavin T (ThT) fluorescence method was used to detect the effects of peptides (50 μM) on Aβ (25 μM) aggregation inhibitory effect.

Results: The results showed that the CScore of YVRHLKYVRHLK peptide molecule docking was 10.0608, the predicted activity score was 0.20, and the KD value was 5.385 × 10-5. The ThT and CCK-8 kit method found that the peptide itself is less toxic to PC12 cells at a concentration of 50 μM, and it has a significant inhibitory effect on the formation of Aβ_1-42 aggregates when incubated with Aβ_1-42 at a ratio of 1:1 (p < 0.05) and can significantly reduce the PC12 cytotoxicity induced by Aβ_1-42 (p < 0.05).

Conclusion: In conclusion, the polypeptide YVRHLKYVRHLK designed in this study has a neuroprotective effect on PC12 cytotoxicity induced by Aβ_1-42. Graphical Abstract.

Keywords: Aβ; PC12 cells +; molecular docking; neuroprotection; neuroscience.