Vibrational Raman optical activity (ROA) spectra of the calcium-binding lysozyme from equine milk in native and nonnative states are measured and compared with those of the homologous proteins hen egg white lysozyme and bovine ␣-lactalbumin. The ROA spectrum of holo equine lysozyme at pH 4.6 and 22°
Molten globule state of equine β-Lactoglobulin
✍ Scribed by Masamichi Ikeguchi; Shin-ichi Kato; Akio Shimizu; Shintaro Sugai
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 165 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0887-3585
No coin nor oath required. For personal study only.
✦ Synopsis
The acid-unfolded state of equine beta-lactoglobulin was characterized by means of circular dichroism, nuclear magnetic resonance, analytical gel-filtration chromatography, and analytical centrifugation. The acid-unfolded state of equine beta-lactoglobulin has a substantial secondary structure as shown by the far-ultraviolet circular dichroism spectrum but lacks persistent tertiary packing of the side chains as indicated by the near-ultraviolet circular dichroism and nuclear magnetic resonance spectra. It is nearly as compact as the native conformation as shown by the gel filtration and sedimentation experiments, and it has the exposed hydrophobic surface as indicated by its tendency to aggregate. All of these characteristics indicate that the acid-unfolded state of equine beta-lactoglobulin is a molten globule state. The alpha helix content in the acid-unfolded state, which has been estimated from the circular dichroism spectrum, is larger than that in the native state, suggesting the presence of nonnative alpha helices in the molten globule state. This result suggests the generality of the intermediate with nonnative alpha helices during the folding of proteins having the beta-clam fold.
📜 SIMILAR VOLUMES
## Abstract Cytochrome __c__ (cyt __c__) undergoes a poly(vinylsulphate) (PVS)‐induced transition at slightly acidic pH into a molten globule‐like state that resembles the effect that negatively charged membrane surfaces have on this protein. In this work, the thermodynamic properties of the molten
Thermal and denaturant-induced transitions of the acid molten globule state of bovine ␣-lactalbumin (acid [A] state) are analyzed by scanning calorimetry, titration calorimetry, viscosimetry, and derivative spectroscopy. A denaturant-induced heat effect of the A state is shown by a calorimetric diff