Elucidating the Structure-Function Relationship in Novel PET-Degrading Enzymes

• Grant number: 24/10898-9
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: October 19, 2024
• End date: October 18, 2025
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Fábio Márcio Squina
• Grantee: Iara Ciancaglini
• Supervisor: Gideon John Davies
• Host Institution: Pró-Reitoria de Pós-Graduação, Pesquisa, Extensão e Inovação. Universidade de Sorocaba (UNISO). Sorocaba , SP, Brazil
• Institution abroad: University of York, England
• Associated to the scholarship: 22/14112-4 - Development of a collection of extreme thermophilic enzymes active in the conversion of pet plastics, BP.DD

Abstract

Petroleum-based plastics (PBP) find multiple uses due to their lightness, transparency, and resistance, the latter attributed to their chemical inertness. However, the environmental challenges arising from the slow degradation of plastics have positioned them as adversaries. In response, initiatives are currently underway to tackle the accumulation of plastics in landfills and natural environments. Novel bacterial species have been described to efficiently degrade PBP, including Ideonella sakaiensis, which grows in polyethylene terephthalate (PET) as the sole carbon source through the action of two main esterases: IsPETase and MHETase. This discovery represents a milestone in understanding the hidden mechanisms evolved by nature to break down synthetic polymers. It also suggests that enzymes produced by microorganisms have been repurposed to bind and cleave synthetic polymers, considering that the first plastic patent dates to 1950. While research on PAZymes is still in its infancy, several studies have addressed the potential applicability of esterases, lipases, cutinases, carboxylesterases, and polyesterase-cutinase-lipases in an industrial context, like in plastic-recycling facilities. In this context, this project aims to gain mechanistic insights into the structure and function of two novel PETase members of the polyesterase-cutinase-lipases ESTHER family, aiming to pave the way for developing robust biocatalysts with enhanced catalytic performance through rational protein design.