BIFI–Talk: Sara García Linares. Universidad Complutense de Madrid.

Title: Design of nanoreactors for plastic depolymerization based on pore-forming toxins

Abstract
Petroleum-based plastics are durable and accumulate in all ecological niches. Approximately 80% of waste objects are made of macroplastics, with most ending up dumped into the oceans. PET (polyethylene terephthalate) is the primary component in many synthetic fibers and water bottles, comprising 14.4% of total plastic waste. Our work focuses on improving biotechnological processes for PET degradation by designing more efficient enzymes. To achieve this, we design biocatalytic nanopores using computational modeling, based on the homo-octamer of a sea anemone toxin that forms pores in biological membranes. These pores are assembled into nanodiscs, forming individual water-soluble particles. At a temperature of only 40 °C and neutral pH, this biocatalytic nanoreactor can degrade PET nanoparticles from plastic bottles and other commercial versions of PET used in manufacturing plastic products. The products of these reactions include soluble BHET dimer, BHET itself, and mono-(2-hydroxyethyl)-terephthalic acid (MHET). The results obtained so far constitute a proof-of-concept for building biodegradable pore-based catalytic nanoreactors that could drive new developments in nanobiotechnology. This is exemplified by efficient systems for decomposing PET at levels comparable to the best-performing known engineering PETases, and moreover, at relatively low temperatures.

References
A. Robles-Martín, R. Amigot-Sánchez, S. Roda, […], S. García-Linares*, M. Ferrer*, V. Guallar* (2023). “Sub-micro- and nano-sized polyethylene terephthalate deconstruction with engineered protein nanopores”. Nature Catalysis 6, 1174–1185. DOI: 10.1038/s41929-023-01048-6.

FRIDAY, 21st June 2024, 12:00 h
Edificio I+D (Conference room)