Unveiling the KRAS Relationship between Affinity and Dynamics: A Molecular Simulations Study

Area of Science:

• Biochemistry
• Computational Biology
• Drug Discovery

Background:

• Kirsten rat sarcoma virus protein (KRAS) is a key target in cancer drug discovery.
• Its structural flexibility and shallow binding pocket present significant challenges for drug development, historically deeming it 'undruggable'.
• Understanding KRAS structure and dynamics is crucial for advancing therapeutic strategies against cancer.

Purpose of the Study:

• To investigate the challenges of targeting KRAS in computational drug design.
• To characterize KRAS structural flexibility and molecular interactions.
• To quantify the thermodynamic stability of the KRAS G12C mutant and explore fragment screening methods.

Main Methods:

• Utilized molecular dynamics simulations to analyze KRAS protein structure and dynamics.
• Employed thermodynamic cycles to assess the stability of the G12C mutant.
• Applied Accelerated Enveloping Distribution Sampling (A-EDS) for fragment screening and binding affinity quantification.

Main Results:

• Characterized KRAS structural flexibility and diverse molecular interactions.
• Quantified thermodynamic reasons for the enhanced stability of the G12C mutant in its active state.
• Demonstrated A-EDS's capability for efficient fragment screening and relative binding free energy calculations.

Conclusions:

• Molecular dynamics simulations provide insights into KRAS targeting challenges.
• Thermodynamic analysis supports experimental observations of KRAS mutant stability.
• A-EDS is an effective method for identifying and quantifying binding affinities of potential KRAS inhibitors.