Examining the Autocatalytic Cleavage and Reassembly of Nylonases (TvgC, TslC and TbcC) for Nylon Degradation
Bibliographic record
Abstract
Plastics play a crucial role in modern society, yet their durability and resistance to degradation result in challenges for waste management and environmental sustainability. Current estimates indicate that global plastic production exceeds 400 million tonnes annually, with only 9% of waste recycled. The biocatalytic degradation of plastic is an emerging sustainable solution to mitigate plastic pollution. Advances in this field show promising results for the degradation of Polyethylene Terephthalate (PET); however, effective strategies to degrade other plastics, such as nylon, a polymer used in the textile, automotive, and packaging industries, remain limited. To date, a class of nylonases called 6-aminohexanoate oligomer endohydrolases (NylCs) have been identified, but these enzymes have been insufficient to fully degrade nylon at an industrial scale. TvgC, a novel NylC found through a sequence similarity network (SSN) with known NylCs, shows remarkable catalytic activity towards the degradation of nylon-6 and nylon 6-6. TvgC functions through an autocatalytic cleavage mechanism to release Thr234 as its N-terminal nucleophile before assembling into the active protein, characteristic of the N-terminal nucleophile (Ntn) hydrolase family. This generates an N- and a C-terminal fragment, which assemble via non-covalent interactions to form a heterodimer. A recent study shows that the autocatalytic cleavage of TvgC requires 24 hours of heating at 50°C, which is inefficient for industrial applications. Two other NylCs have been identified from the same SSN, TslC and TbcC, which are expected to degrade nylon with an analogous mechanism to TvgC. The current research project aims to determine if independently expressed N-terminal and C-terminal halves of TvgC, TslC and TbcC can reassemble into an active, nylon-degrading protein, eliminating the time required for autocatalytic cleavage. Addressing this question will expand our understanding of the autocatalytic cleavage and reassembly mechanisms and support the development of nylonases that can recycle plastic industrially with increased efficiency.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".