Inactivation and conformational changes of creatine kinase at low concentrations of hexafluoroisopropanol solutions
Bibliographic record
Abstract
Using the methods of far-ultraviolet circular dichroism (CD) spectra, fluorescence spectra, and enzyme activity assays, the inactivation and conformational changes of creatine kinase (CK) induced by 1,1,1,3,3,3-hexafluoro-2-propanol (hexafluoroisopropanol (HFIP)) of different concentrations were investigated. To avoid the aggregation of CK that occurs with high HFIP, concentrations of 0%-5% HFIP were used in this study. The CD spectra showed that HFIP concentrations above 2.5% strongly induced the formation of secondary structures of CK. No marked conformational changes were observed at low concentrations of HFIP (0%-2.5%). After incubation with 0.2% HFIP for 10 min, CK lost most of its activity. The kinetic theory of the substrate reaction during irreversible inhibition of enzyme activity described previously by Tsou was applied to study the kinetics of CK inactivation during denaturation by HFIP. The inactivation rate constants for the free enzyme and the substrate-enzyme complex were determined by Tsou's method. The results suggested that low concentrations of HFIP had a high potential to induce helices of protein and that the active site of the enzyme was situated in a limited and flexible region of the enzyme molecule that was more susceptible to the denaturant than was the protein as a whole.
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 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) | 0.001 | 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 | 0.000 |
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".