Scientists decrypt the mechanism of a key photoenzyme that can be used in green chemistry and biofuels
Researchers decrypted fatty acid photodecarboxylase (FAP) The operating mechanism of FAP is naturally present in microscopic algae such as chlorella. This enzyme was proven in 2017 to use light energy to form hydrocarbons from the fatty acids produced by these microalgae. In order to achieve this new result, the research team used a complete set of experimental and theoretical tools.
It is important to understand the working principle of FAP, because this photoenzyme opens up new opportunities for the sustainable production of biofuels using fatty acids naturally produced by organisms. FAP is also very promising in the production of high value-added compounds in fine chemicals, cosmetics and pharmaceuticals.
In addition, due to light-induced reactions , This photoenzyme can obtain the ultra-fast phenomenon that occurs in the enzymatic reaction process. Therefore, FAP provides a unique opportunity to understand in detail the chemical reactions that occur in the organism.
More specifically, in this work, the researchers showed that when FAP is illuminated and absorbs a photon, an electron is stripped from the fatty acid produced by the algae within 300 picoseconds. This fatty acid is then dissociated into hydrocarbon precursors and carbon dioxide. Then, most of the carbon dioxide produced is converted into bicarbonate in the enzyme within 100 nanoseconds. This activity uses light, but does not hinder photosynthesis: the flavin molecules that absorb photons in FAP are bent. This conformation turns the absorption spectrum of the molecule to red, so it uses photons that are not used by the photosynthetic activity of microalgae.
It is the international consortium’s comprehensive interpretation of the results of various experimental and theoretical methods that have resulted in detailed, atomic-scale pictures of FAP’s work. This multidisciplinary research combines bioengineering work, optical and vibrational spectroscopy, static and dynamic crystallography using synchrotron or X-ray free electron lasers, and quantum chemical calculations.