Two-Dimensional Infrared Correlation Spectroscopy as a Probe of Sequential Events in the Thermal Unfolding of Cytochromes <i>c</i>
Bibliographic record
Abstract
The sequential unfolding events of horse, cow, and tuna ferricytochromes c (cyt c) as a function of increasing temperature over the range 25-81 degrees C were investigated by resolution-enhanced two-dimensional infrared (2D IR) correlation spectroscopy. The 2D IR analysis revealed that in the thermal denaturation of the two mammalian cyts, the overall sequence of unfolding is similar, with denaturation of extended-chain and turn structures occurring prior to unfolding of alpha-helices, followed by denaturation of residual stable extended-chain structures. In tuna cyt c, denaturation of all extended-chain structures precedes the unfolding of alpha-helices. Moreover, in cow cyt c, unfolding of all helical components occurs as one cooperative unit, but in horse and tuna cyts c, the helical components behave as subdomains that unfold separately, as proposed recently by Englander and co-workers for horse cyt c [Bai et al. (1995) Science 269, 192-197; Milne et al. (1999) J. Mol. Biol. 290, 811-822]. At higher temperatures, following the loss of secondary structure, protein aggregation occurs in the three cyts c. The data presented here establish that variations in the thermal unfolding of cyts c can be associated with specific sites in the protein that influence local flexibility yet have little affect on global stability. This study demonstrates the power of resolution-enhanced 2D IR correlation spectroscopy in probing unfolding events in homologous proteins.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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".