Mutations of a PET hydrolyzing enzyme PET2 resulted in a 6.7 degrees C increase in thermal stability and a 6.8-fold increase in PET hydrolytic activity. Tm represents melting (denaturation) temperature and colors on enzyme structures show their surface charges (blue: positive, red: negative).
Cheap to produce and long to degrade, plastic was once a manufacturing miracle. Now, plastic is an environmental plague, clogging landfills and choking waterways. A Japan-based research team has turned back to nature to develop an approach to degrading the stubborn substance. Similar to how a protein binds to cellulose in plants or to chitin in crustaceans to initiate decomposition, an engineered protein is on its way to binding to plastic particles in an effort to more efficiently break them down.
They published their results on June 29 in ACS Catalysis, a journal of the American Chemical Society.
“Polyethylene terephthalate (PET) is produced and used in large quantities in modern society due to its low cost and ease of processing,” said paper author Ryota Iino, professor of the Institute for Molecular Science (IMS) in the National Institutes of Natural Sciences (NINS). “However, in recent years, from the perspective of realizing a sustainable society, the complete recycling of PET in industry and the removal of PET from the natural environment have become global issues. To resolve these issues, it is very important to understand how to degrade PET efficiently.”
The researchers investigated and engineered an enzyme cloned from a library of genetic materials collected from nature. This enzyme — called PET2 — was found to facilitate the degradation of PET by accelerating the reaction between PET’s chemical components and water.
Using single-molecule imaging analysis, the team found that the way the enzyme binds to the surface of PET actually limited the rate of degradation.
“We also revealed that by introducing positive charges on the surface of PET-degrading enzyme, the binding rate to the PET surface can be increased,” Iino said.
The positive charges react favorably to the PET surface, so more of the enzyme can bind and more effectively degrade the PET. The researchers also found that while engineered PET2 showed high thermal stability and highest activity at 68 degrees Celsius — slightly lower than most residential kitchen ovens can go — it may be more effective at higher temperatures where PET’s molecular bonds become more flexible and breakable.
“Our ultimate goal is to create a bacterium that can sense PET in the environment, move toward it, and degrade it,” Iino said. Such a bacterium would then be able to turn the degraded PET into energy useful for other organisms, effectively acting as an automated recycling center for plastic. “In nature, chitin and cellulose are recycled in this way.”
Iino is also affiliated with the School of Physical Sciences at The Graduate University for Advanced Studies (SOKENDAI). Other contributors include Akihiko Nakamura, Department of Applied Life Sciences, Faculty of Agriculture, Shizuoka University, and the Shizuoka Institute for the Study of Marine Biology and Chemistry; and Naoya Kobayashi and Nobuyasu Koga, Exploratory Research Center on Life and Living Systems (ExCELLS), NINS. Koga is also affiliated with IMS, NINS, and SOKENDAI.
The Leading Initiative for Excellent Young Researchers, the Ministry of Education, Culture, Sports, Science, and Technology of Japan, the Sumitomo Foundation, and the ExCELLS Special Collaboration Program supported this research.
Original Article: Engineered protein inspired by nature may help plastic plague
The Latest Updates from Bing News & Google News
Go deeper with Bing News on:
- Scientists examine how a Parkinson’s disease-linked protein attacks a cell’s powerhouseson August 24, 2021 at 5:15 am
UB biologists explore how alpha-synuclein, associated with Parkinson’s disease, damages mitochondria, organelles that produce most of a cell’s energy.
- How A Parkinson’s Disease-linked Protein Attacks Mitochondriaon August 20, 2021 at 7:59 am
WASHINGTON — Mitochondria, the powerhouse of the cell, may actually be beneficial when split into fragments, according to new research. It demonstrates ...
- CRISPR pioneer Feng Zhang's latest work delivers mRNA, gene therapy with a human proteinon August 19, 2021 at 11:00 am
COVID-19 mRNA vaccines and existing gene therapies, including those built with the CRISPR-Cas9 gene-editing tool, are delivered into cells with viral vectors or lipid nanoparticles. A research team ...
- How a Parkinson's disease protein attacks mitochondraon August 19, 2021 at 9:55 am
A new study has shown how a protein associated with Parkinson disease can damage the mitochondria organelles inside cells that carry out a medley of vital ta ...
- New study discovers how Parkinson’s-linked protein attacks mitochondriaon August 19, 2021 at 7:03 am
Researchers used fruit fly larvae to explore how alpha-synuclein impacts the mitochondria, advancing the study of Parkinson’s disease.
Go deeper with Google Headlines on:
Go deeper with Bing News on:
Degradation of PET
- Plastic waste being converted into hydrogen fuel (VIDEO)on August 22, 2021 at 8:58 pm
PET (polyethylene terephthalate ... The process works by using nanostructured semiconductors to drive the degradation of waste and pathogens with sunlight.
- Fire Update: Smoke to return to the basin tonight; Fires continue to burn across the sierrason August 20, 2021 at 4:10 am
Carson City residents and beyond can expect the smoke to return from the Caldor Fire, as surface winds shift and a degradation in air quality will continue into Saturday and possibly continue ...
- The Materials Analyst, Part 2: Brittle PPOon August 18, 2021 at 5:00 pm
As discussed in the last article (September 1997 IMM) this degradation can come from excessive heat and ... A match with our in-house library revealed that the most likely contaminant was PET ...
- Thermally Stable and Flame Retardant Polymer Nanocompositeson August 13, 2021 at 12:27 am
Mechanism of thermal degradation of layered silicates modified with ammonium ... Kamal and Jorge Uribe-Calderon 4. PET nanocomposites using nanoclays modified with thermally stable surfactants ...
- Medical Tubing: Dimensions Aren’t Everythingon August 12, 2021 at 5:00 pm
Some polymers, such as polyethylene terephthalate (PET), are very sensitive to process parameters and can degrade easily, while other polymers, such as polyethylene, are very forgiving. Degradation ...