Preserved Transmembrane Segment Topology, Structure, and Dynamics in Disparate Micellar Environments
Bibliographic record
Abstract
Detergent micelles are frequently employed as membrane mimetics for solution-state membrane protein nuclear magnetic resonance spectroscopy. Here we compare topology, structure, ps-ns time-scale dynamics, and hydrodynamics of a model protein with one transmembrane (TM) segment (residues 1-55 of the apelin receptor, APJ, a G-protein-coupled receptor) in three distinct, commonly used micellar environments. In each environment, two solvent-protected helical segments connected by a solvent-exposed kink were observed. The break in helical character at the kink was maintained in a helix-stabilizing fluorinated alcohol environment, implying that this structural feature is inherent. Molecular dynamics simulations also substantiate favorable self-assembly of compact protein-micelle complexes with a more dynamic, solvent-exposed kink. Despite the observed similarity in TM segment behavior, micelle-dependent differences were clear in the structure, dynamics, and compactness of the 30-residue, extramembrane N-terminal tail of the protein. This would affect intermolecular interactions and, correspondingly, the functional state of the membrane protein.
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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) | 0.000 | 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 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".