Proteins and enzymes spark off chemical reactions
An olefin is a molecule with a carbon-carbon double bond. In olefin metathesis (OM), the double bond carbons change partners and form two new olefins. The introduction of stable and selective catalysts for OM has greatly simplified the construction and rearrangement of carbon-carbon double bonds. This organic reaction has been widely used in research and industrial applications to produce catalysts for use in medicines and polymers, as well as for enhancing fuel properties. With molecular biology and techniques to artificially create DNA (recombinant DNA), chemists can now 'evolve' their own catalysts. To achieve this, the 'Constructing an artificial enzyme for olefin metathesis' (AEOM) project focused on two relatively unexplored areas of the OM reaction. First, selectivity problems were addressed in cross metathesis. This is a special kind of OM reaction that until now has not proven its ability for high-yield olefin production. Second, researchers sought to study the potential applications of OM in chemical biology. One of the project's main goals was to develop its own special metathesis catalysts: artificial metathesis enzymes. In one experiment, a catalyst was successfully coupled to the protein and the site of attachment was confirmed. The protein-catalyst complex was then characterised, giving good evidence that the desired conjugate had been formed. Although a number of OM reactions were tested in water, no activity was seen with the protein-catalyst conjugate under all conditions tested. Two experiments were performed to test this hypothesis. The hybrid catalyst was treated to digest most of the protein, thus leaving the catalyst more exposed. It was then subjected to standard conditions for OM. Results showed that although the protein deactivates the catalyst, it does not destroy it.
