Understanding and Harnessing Enzymes for Organosilicon Chemistry

In synthetic chemistry, there has been increasing prominence in the use of engineered enzymes to execute chemical transformations. These biocatalysts are attractive since they offer highly efficient synthesis in terms of yields and selectivity; together with an inherent environmental sustainability. However, one area where biocatalysis has been relatively unexplored is in silicon-containing (organosilicon) chemistry. Such organosilicon compounds are present in a huge variety of consumer products and play a major role in organic synthesis. Furthermore, such compounds exhibit desirable physical properties that are difficult to achieve by other materials.
Marine sponges use silicon (in the form of silica) as part of their inorganic skeleton and utilise an enzyme termed "silicatein" to polymerise silicic acid (H4SiO4) into silica. This family of enzymes are uniquely interesting as they catalyse a reaction that is rare in living systems, the formation of Si-O bonds. Recently, work by the supervisory team has shown that silicatein is also able to catalyse the hydrolysis and condensation (i.e. bond forming and bond breaking) with organosiloxanes, opening the possibility of using this enzyme to facilitate the synthesis of advanced organic-inorganic hybrid materials.
This research therefore proposes to exploit the silicateins through rational modification of their structure and apply them to the development of new synthetic reactions. The goals of this project will be two-fold: (i) to improve our understanding of the enzymes' molecular mechanism; and (ii) develop new biocatalysts for organosilicon chemistry with wide scope yet high selectivity. Together this research will contribute to the application of enzyme catalysts in industrial biotechnology