Bioinspired enzymatic synthesis of silica nanocrystals provided by recombinant silicatein from the marine sponge Latrunculia oparinae

The process of silica formation in marine sponges is thought to be mediated by a family of catalytically active structure-directing enzymes called silicateins. It has been demonstrated in biomimicking syntheses that silicateins facilitated the formation of amorphous SiO₂. Here, we present evidence that the silicatein LoSiLA1 from the marine sponge Latrunculia oparinae catalyzes the in vitro synthesis of hexa-tetrahedral SiO₂ crystals of 200–300 nm. This was possible in the presence of the silica precursor tetrakis-(2-hydroxyethyl)-orthosilicate that is completely soluble in water and biocompatible, experiences hydrolysis–condensation at neutral pH and ambient conditions.