New mechanisms of P450: an enzymatic strategy for renewable hydrocarbons

Abstract

Researchers around the world driven by real environmental concerns due to increases in atmospheric CO2 levels and global temperatures have been making efforts to create advanced platforms for the production of renewable and sustainable biofuels. Drop-in biofuels consist of biohydrocarbons (or renewable hydrocarbons), formed by medium and long chains of alkenes/alkanes, which have chemical compositions and physical characteristics similar to conventional petroleum fuels. These properties ensure the sharing of infrastructure already used in the distribution of gasoline, diesel and aviation fuel and compatibility with the current engines of road, sea and air transport vehicles. However, the greatest challenge for the production of drop-in from plant biomass is the presence of oxygenated intermediates, since the oxygen present in the chemical structure of the biofuel can damage parts and engines of vehicles. Currently, deoxygenation occurs via thermochemical processes based on the use of hydrogenation (large amount of H2), high temperatures and heavy metals. These processes are aggressive to the environment, which makes it necessary to study soft biological routes that cause less environmental damage. Thus, the identification and complete understanding of enzymes capable of producing alkanes/alkenes become increasingly fundamental, as recently emphasized in a publication in Science - "Enzymes make light work of hydrocarbon production" (Scrutton, 2017). In recent years, the decarboxylase/peroxygenase called OleTJE belonging to the 152 family of the P450 superclass has gained great notoriety in the scientific and industrial communities due to the fact that it has a unique property that is to remove oxygen from the long chain fatty acid (C12-C20) producing a product, 1-alkene. However, little is known about the functional/molecular mechanics of peroxygenases, since few enzymes of this family have been reported so far. In view of the above, this research project proposes to discover and explore new P450 peroxygenases that are functionally active in the decarboxylation of fatty acids. With this project, we intend to understand and elucidate the main components responsible for favoring the decarboxylation reaction for the formation of alkenes. For this, a combination of structural, spectroscopic, biochemical and bioinformatics methods will be used that are already extensively used in our research group. At least to our knowledge, our group will be a pioneer in the elucidation of this new family of P450 and therefore, we can contribute to increasing the arsenal of decarboxylases besides generating unprecedented knowledge and extremely relevant to the area of industrial biotechnology. (AU)