Molecular studies of photo-activated enzymes that produce petroleum bio-replicas

• Grant number: 23/13770-0
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: March 01, 2024
• End date: February 29, 2028
• Field of knowledge: Biological Sciences - Biochemistry - Enzymology
• Principal Investigator: Leticia Maria Zanphorlin
• Grantee: Eduardo Crespi Souza Rocha
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

The exponential growth of the world population has caused a significant impact on the increasing demand for energy, necessary to meet both the essential needs of society and to drive the economic and industrial development of countries. This phenomenon has resulted in unbridled and unsustainable exploitation of non-renewable natural resources, primarily fossil-based, thereby intensifying the problem of global warming and its devastating consequences. Faced with this reality, it is necessary to adopt and implement alternatives that seek a transition from the current energy model to a more sustainable and ecologically responsible one. Fatty acid decarboxylases have emerged as a powerful alternative for the biological production of alkanes and alkenes (olefins), providing a sustainable route for the production of drop-in fuels and substitutes for petrochemicals. Recently, our research group unveiled a new decarboxylase from the CYP152 P450 family, which exhibits robust functional characteristics, metabolizes both saturated and unsaturated fatty acids, and catalyzes the decarboxylation reaction through a previously undescribed mechanism. Encouraged by these results, in this doctoral project, we will focus on the study of photoenzymes (FAPs) that are predicted to produce alkanes, petroleum-replica molecules. The literature reports the characterization of two FAPs from Chlorella variabilis and Chlamydomonas reinhardtii, with only the former having a resolved tertiary structure. Furthermore, it is known that these enzymes undergo inhibition when exposed to light for extended periods and metabolize unsaturated fatty acids poorly. In light of the above, the central objective of this doctoral project is to explore different clusters previously mapped by our research group, with the aim of discovering new photo-oxidative decarboxylases. We will employ biochemical, biophysical, and structural methods to understand the stability, specificity, structure, and catalytic performance of these new enzymes. Rational mutations will also be proposed and carried out to enhance catalytic activity towards different fatty acids. Therefore, this project has the potential not only to boost the production of aviation biofuels and green diesel, both based on alkanes, but also to contribute to the molecular understanding of light-activated enzymes present in various nature reactions.