The use of 5-tert-butylproline to study nucleation of polyproline type I conformation
Bibliographic record
Abstract
Prolyl amide geometry dictates two kinds of helical conformations in polyproline [1]. Nterminal amides to proline are all cis-isomers in type I polyproline (PPI), which is a right handed helix with an axial translation of 190 pm. Type II polyproline (PPII) is a left handed helix with an axial translation of 320 pm due to the prolyl amides existing as trans-isomers. Peptides adopting PPII conformations have been observed to bind to kinases, SH2 and SH3 domains, and MHC class II proteins by NMR spectroscopy and X-ray crystallography [2]. Because of conformational lability, PPI has been studied mostly in the solid state by X-ray diffraction and little is known about this peptide structure and its relevance in protein biology [1-3]. In order to better characterize the physical and biological properties of PPI, we are using the steric interactions of 5-alkylprolines to augment cis-isomer populations in polyproline helices. We report attempts to induce PPI geometry in water by incorporating 5tert-butylproline (tBuPro) into polyproline hexamers as studied by NMR and CD spectroscopy.
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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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
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".