Molecular dynamics simulation of protein-mediated biomineralization of amorphous calcium carbonate.

The protein-mediated biomineralization of calcium carbonate (CaCO) in living organisms is primarily governed by critical interactions between the charged amino acids of the protein, solvent, calcium (Ca) and carbonate (CO ) ions. The present article investigates the molecular mechanism of lysozyme-mediated nucleation of amorphous calcium carbonate (ACC) using molecular dynamics and metadynamics simulations. The results reveal that, by acting as nucleation sites, the positively charged side chains of surface-exposed arginine residues form hydrogen bonds with carbonates and promote aggregation of ions around them leading to the formation and growth of ACC on the protein surface.