# Insights into Binding Mechanisms of Potential Inhibitors Targeting PCSK9 Protein via Molecular Dynamics Simulation and Free Energy Calculation

## TL;DR

This study identifies a potential small-molecule inhibitor for PCSK9, a protein linked to heart disease, and reveals key interactions that could help design better treatments.

## Contribution

The study identifies key residues and binding patterns of a potential PCSK9 inhibitor using MD simulations and free energy calculations.

## Key findings

- ARG237, ILE369, ARG194, and PHE379 are critical hot-spot residues in PCSK9–inhibitor binding.
- Polarization effects significantly influence PCSK9–ligand interactions.
- The inhibitor shows similar binding patterns to known active compounds, aiding inhibitor design.

## Abstract

The design of small-molecule inhibitors targeting proprotein convertase subtilisin/Kein type 9 (PCSK9) remains a forefront challenge in combating atherosclerosis. While various monoclonal antibodies have achieved clinical success, small-molecule inhibitors are hindered by the unique structural features of the PCSK9 binding interface. In this study, a potential small-molecule inhibitor was identified through virtual screening, followed by molecular dynamics (MD) simulations to explore the binding mechanisms between the inhibitor and the PCSK9 protein. Binding free energies were calculated using molecular mechanics/Generalized Born surface area (MM/GBSA) with the interaction entropy (IE) method, and critical hot-spot residues were identified via alanine scanning analysis. Key residues, including ARG237, ILE369, ARG194 and PHE379, were revealed to form critical interactions with inhibitor and play dominant roles during the inhibitor’s binding. In addition, the polarization effect was shown to significantly influence PCSK9–ligand binding. The identified inhibitor exhibited highly similar binding patterns with two known active compounds, providing valuable insights for the rational design and optimization of small-molecule inhibitors targeting PCSK9. This work contributes to the development of more effective treatments for hyperlipidemia and associated cardiovascular diseases.