The Role of Lysozyme in the Formation of Bioinspired Silicon Dioxide

Several organisms are able to polycondensate tetraoxosilicic(IV) acid to form silicon(IV) dioxide using polycationic molecules. According to an earlier mechanistic proposal, these molecules undergo a phase separation and recent experimental evidence appears to confirm this model. At the same time, polycationic proteins like lysozyme can also promote polycondensation of silicon(IV) dioxide, and they do so under conditions that are not compatible with liquid-liquid phase separation. In this manuscript we investigate this conundrum by molecular simulations.The mechanism of formation of silica templated by lysozyme is here interrogated using molecular dynamics simulations. The results strongly suggest that the - densely charged - protein electrostatically attracts the precursor and can thus accelerate the polycondensation reaction by increasing its concentration. image