Understanding and Harnessing Enzymes for Organosilicon Chemistry

在合成化学中，利用工程酶来进行化学转化已经越来越突出。这些生物催化剂具有吸引力，因为它们在产率和选择性方面提供了高效的合成；加上固有的环境可持续性。然而，生物催化的一个相对未开发的领域是含硅（有机硅）化学。这种有机硅化合物存在于各种各样的消费品中，在有机合成中起着重要作用。此外，这种化合物表现出其他材料难以达到的理想物理性质。海洋海绵使用硅（以二氧化硅的形式）作为其无机骨架的一部分，并利用一种称为“硅蛋白”的酶将硅酸（H4SiO4）聚合成二氧化硅。这个酶家族非常有趣，因为它们催化了一种在生命系统中罕见的反应，即Si-O键的形成。最近，该研究小组的工作表明，硅蛋白也能够催化有机硅氧烷的水解和缩合（即成键和断键），从而开启了使用这种酶促进高级有机-无机杂化材料合成的可能性。因此，本研究提出通过合理的结构修饰来开发硅蛋白，并将其应用于新的合成反应的开发。这个项目的目标是双重的：(i)提高我们对酶的分子机制的理解；(2)开发范围广、选择性高的有机硅化学用新型生物催化剂。本研究将有助于酶催化剂在工业生物技术中的应用

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