Solvation influences flap collapse in HIV-1 protease

Area of Science:

• Biochemistry
• Structural Biology
• Computational Chemistry

Background:

• HIV-1 protease (HIVp) is a key target for AIDS therapy and a model for structure-based drug design.
• The flap region of HIVp exhibits significant flexibility, undergoing conformational changes upon ligand binding.
• Accurate modeling of HIVp flexibility is essential for advancing structure-based drug design.

Purpose of the Study:

• To investigate the influence of solvation on HIV-1 protease flap rearrangement using molecular dynamics simulations.
• To identify and mitigate artifacts in modeling protein flexibility caused by system setup procedures.

Main Methods:

• Conducted 3-nanosecond molecular dynamics simulations of HIV-1 protease.
• Varied system setup, specifically focusing on solvation routines and vacuum space reduction.
• Employed extended equilibration procedures to ensure system stability.

Main Results:

• Initial rapid flap movement observed in simulations may be an artifact of system solvation creating vacuum regions.
• Reducing vacuum space during solvation attenuated the observed flap collapse.
• More thorough equilibration preserved a more stable protein conformation throughout the simulations.

Conclusions:

• System setup, particularly solvation and equilibration, significantly impacts the observed dynamics of HIV-1 protease flap flexibility.
• Careful attention to these parameters is critical for reliable molecular dynamics simulations in drug design.
• This study provides insights into refining simulation methodologies for flexible protein targets.