First Carbon-Silicon Bond Successfully Created Using Enzymes
Silicon is the second most abundant element in the Earth’s crust, with oxygen being the first. It is used commercially without being separated and often needs little processing. The construction industry uses silicon in building materials; other uses are in glass and ceramics.
The modern world economy owes a great deal to elemental silicon, which is used widely in the steel and chemical industries. Purified silicon is used in semiconductor elements – an essential component inside all of our computers.
Scientists have now discovered that living organisms can be persuaded to make silicon-carbon bonds. They first used a method called directed evolution, in which new and better enzymes are created in the laboratory by artificial selection.
Enzymes are a class of proteins that catalyse chemical reactions. The protein was found from a bacterium that grows in hot springs in Iceland. This protein is called cytochrome C and usually shuttles electrons to other proteins, but researchers discovered that it acts like an enzyme to create silicon-carbon bonds at low levels. After mutating the DNA coding from that protein after three rounds of mutation, they created an enzyme that can make silicon-carbon bonds fifteen times more efficiently than the best synthetic catalyst invented by chemists.
The synthetic process for making silicon-carbon bonds is an expensive one because it uses precious metals and toxic solvents and leaves you with unwanted by-products, whereas the genetically encoded catalyst is non-toxic, cheaper and easier to modify. It is iron-based and can be modified at room temperature or in water, and because the enzyme is highly selective, it makes fewer unwanted by-products.
This opens up new pathways for synthetic biology and advances in chemistry, biology, computer science and engineering and will enable experts to create new foundations for many sectors, including medicine, energy and the environment. The possibilities are endless. Carbon-silicon bonds are found in hundreds of products, from drugs and medical implants to paints, and in sealants and metal bonding adhesive from companies such as http://www.ct1ltd.com/. The new enzyme-based catalyst will possibly offer a more sustainable alternative to the expensive metal catalysts of today.
So What Next?
There are a number of drugs on the market which use silicon but are expensive to make. New drugs can be developed less expensively, therefore creating an improved outcome for all patients.