How to Sample Dozens of Substitutions per Site with λ Dynamics

Area of Science:

• Computational chemistry
• Biophysics
• Drug design

Background:

• Alchemical free energy methods use molecular dynamics for accurate predictions.
• Lambda dynamics excels at exploring vast chemical spaces compared to pairwise methods.
• Previous lambda dynamics methods were limited to <10 substituents per site.

Purpose of the Study:

• To overcome the limitations of lambda dynamics in exploring large chemical spaces.
• To enable the simulation of systems with a higher number of substituents per site.
• To improve the efficiency and scalability of alchemical free energy calculations.

Main Methods:

• Introduction of novel biasing potentials to favor physical end states.
• Development of a scalable adaptive landscape flattening algorithm.
• Application to protein and drug design test systems with up to 24 substituents.

Main Results:

• Successfully circumvented excessive sampling of nonphysical intermediate states.
• Demonstrated efficient sampling in systems with up to 24 substituents per site.
• Enabled simultaneous simulation of all 20 amino acids for the first time.

Conclusions:

• The new methods significantly expand the applicability of lambda dynamics.
• This advancement facilitates more comprehensive exploration in computational design.
• Opens new avenues for complex molecular modeling and design.