The Endothermic Effects during Denaturation of Lysozyme by Temperature Modulated Calorimetry and an Intermediate Reaction Equilibrium
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
To gain insight into the thermodynamics of protein denaturation, the complex heat capacity, C p * (= C p ‘ − iC p ‘ ‘) of lysozyme−water system has been measured at pH 2.5 in the 293−368 K range by using temperature-modulated scanning calorimetry (TMSC), a technique in which the thermally reversible enthalpy changes are measured separately and simultaneously with the thermally irreversible enthalpy changes. The plot of C p ‘ against the temperature T shows a broad peak, which is similar to that observed in C p, DSC, measured here and elsewhere by differential scanning calorimetry (DSC), a technique which gives the sum of both the reversible and irreversible contributions in the apparent heat capacity value. This peak in C p, DSC has been generally attributed to endothermic heat absorption on reversible and irreversible unfolding processes and irreversible thermal denaturation. It is shown that the observed C p ‘ peak results from heat absorption when the equilibrium constant between the native lysozyme state and a conformationally different intermediate state increases with T . The plot of C p ‘ versus T is subdivided into four regions, corresponding to the dominance of a certain process. Thermal denaturation of lysozyme was found to occur according to a scheme, native state ↔ unfolded (intermediate) state → denatured state. This conclusion is consistent with the general view that the first step of denaturation of small one-domain globular protein like lysozyme is a reversible conformational (unfolding) transition, and the second step is irreversible denaturation. It is shown that when kept isothermally at T > 341 K, i.e., within the transition temperature range, C p ‘ of lysozyme decreases. This decrease is exponential in time and corresponds to a rate constant, which varies according to the Arrhenius-type equation, with a preexponential factor of 5 × 10 20 s -1 and energy of 167 kJ/mol. The overall kinetics of the denaturation reaction is of the first order.
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.
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 it