Dipolar dynamic frequency shifts in multiple-quantum spectra of methyl groups in proteins: correlation with side-chain motion
Bibliographic record
Abstract
Small deviations from the expected relative positions of multiplet components in double- and zero-quantum 1H-13C methyl correlation maps have been observed in spectra recorded on a 7-kDa protein. These dynamic frequency shifts (DFS) are the result of dipolar cross-correlations that derive from fields produced by the spins within the methyl groups. The shifts have been quantified and compared with values calculated from a Redfield analysis. Good agreement is noted between the signs of the predicted and experimentally observed relative shifts of lines in both F1 and F2 dimensions of spectra, as well as between the magnitudes of the calculated and observed shifts in the F2 (1H) dimension. The experimental DFS values show a reasonable correlation with 2H relaxation-derived measures of methyl side-chain dynamics, as expected from theory. This suggests that in cases where such shifts can be quantified, they can serve as qualitative measures of motion.
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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".