Bridging Enzymatic Structure Function via Mechanics: A Coarse-Grain Approach

Area of Science:

• Biochemistry
• Structural Biology
• Computational Biology

Background:

• Protein flexibility is crucial for enzyme function, encompassing diverse structural changes upon ligand binding.
• Understanding the mechanical properties of enzymes and how ligand binding influences them is key to deciphering enzymatic activity.

Purpose of the Study:

• To investigate the relationship between enzyme mechanical properties, ligand-induced structural variations, and enzymatic activity.
• To analyze how local residue rigidity contributes to an enzyme's overall structure and function.

Main Methods:

• Coarse-grain Brownian dynamics simulations were performed on enzymes with available unbound and ligand-bound structures from the Protein Data Bank.
• Systematic comparison of enzyme rigidity in unbound versus bound states was conducted.

Main Results:

• Enzymes display significant mechanical heterogeneity, with local residue rigidity correlating with structural and functional roles.
• Ligand binding induces mechanical variations, altering enzyme flexibility through small conformational changes that have significant mechanical effects.
• These mechanical changes concentrate on specific residues critical for enzymatic activity.

Conclusions:

• Enzyme mechanical properties are heterogeneous and directly linked to function.
• Ligand binding can finely tune enzyme flexibility, impacting activity through targeted mechanical variations.
• The simulation approach can identify perturbation-sensitive sites in enzymes, offering insights into protein dynamics and function.