Nonenzymatic Hydration of Phosphoenolpyruvate: General Conditions for Hydration in Protometabolism by Searching Across Pathways
Bibliographic record
Abstract
Numerous reactions within metabolic pathways have been reported to occur nonenzymatically, supporting the hypothesis that life began from a primitive nonenzymatic precursor to metabolism. However, most of those studies reproduce individual transformations or segments of pathways without providing a common set of conditions for classes of reactions that span multiple pathways. In this study, we search across pathways for common nonenzymatic conditions for a recurring chemical transformation in metabolism: alkene hydration. The mild conditions that we identify (Fe oxides such as green rust) apply to all hydration reactions of the rTCA cycle and gluconeogenesis, including the hydration of phosphoenolpyruvate (PEP) to 2-phosphoglycerate (2PGA), which had not previously been reported under nonenzymatic conditions. Mechanistic insights were obtained by studying analogous substrates and through anoxic and radical trapping experiments. Searching for nonenzymatic conditions across pathways provides a complementary strategy to triangulate conditions conducive to the nonenzymatic emergence of a protometabolism.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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) | 0.000 | 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 teacher head, 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".