Flap opening dynamics in HIV-1 protease explored with a coarse-grained model

Area of Science:

• Computational biology
• Biophysics
• Molecular dynamics

Background:

• Protein dynamics are crucial for function, but simulating them at biologically relevant timescales remains challenging.
• Accurate modeling of protein conformational changes is essential for understanding molecular mechanisms and drug design.

Purpose of the Study:

• To present a novel one-bead coarse-grained model for large-scale protein dynamical simulations.
• To validate the model's accuracy using the flap opening dynamics of HIV-1 protease.
• To investigate the thermodynamics and kinetics of protein conformational changes, including solvent effects.

Main Methods:

• Development of a one-bead coarse-grained model with accurate force fields for conformational sampling.
• Application of the model to simulate the flap opening and closing of HIV-1 protease.
• Extensive simulations to achieve long timescales (tens of microseconds) and thorough sampling.

Main Results:

• The model successfully reproduced the experimental structure of the semi-open HIV-1 protease conformation.
• Simulations revealed the thermodynamics and kinetics of the protease flap opening process.
• The study demonstrated that solvent effects significantly slow down protein dynamics to experimentally observed timescales.

Conclusions:

• The developed coarse-grained model enables reliable, long-timescale dynamical simulations of proteins.
• The model accurately captures key aspects of HIV-1 protease dynamics, validating its utility.
• This approach is promising for future applications in areas like substrate docking and drug discovery.