Consistent Picture of the Reversible Thermal Unfolding of Hen Egg-White Lysozyme from Experiment and Molecular Dynamics

Meersman, Filip and Atilgan, Canan and Miles, Andrew J. and Bader, Reto and Shang, Weifeng and Matagne, Andre and Wallace, B. A. and Koch, Michel H. J. (2010) Consistent Picture of the Reversible Thermal Unfolding of Hen Egg-White Lysozyme from Experiment and Molecular Dynamics. BIOPHYSICAL JOURNAL, 99 (7). pp. 2255-2263. ISSN 0006-3495,

Full text not available from this repository. (Request a copy)

Abstract

Synchrotron radiation circular dichroism, Fourier transform infrared, and nuclear magnetic resonance spectroscopies, and small-angle x-ray scattering were used to monitor the reversible thermal unfolding of hen egg white lysozyme. The results were compared with crystal structures and high- and low-temperature structures derived from molecular-dynamics calculations. The results of both experimental and computational methods indicate that the unfolding process starts with the loss of beta-structures followed by the reversible loss of helix content from similar to 40% at 20 degrees C to 27% at 70 degrees C and similar to 20% at 77 degrees C, beyond which unfolding becomes irreversible. Concomitantly there is a reversible increase in the radius of gyration of the protein from 15 angstrom to 18 angstrom. The reversible decrease in forward x-ray scattering demonstrates a lack of aggregation upon unfolding, suggesting the change is due to a larger dilation of hydration water than of bulk water. Molecular-dynamics simulations suggest a similar sequence of events and are in good agreement with the (1)H(N) chemical shift differences in nuclear magnetic resonance. This study demonstrates the power of complementary methods for elucidating unfolding/refolding processes and the nature of both the unfolded structure, for which there is no crystallographic data, and the partially unfolded forms of the protein that can lead to fibril formation and disease.

Item Type: Article
Uncontrolled Keywords: X-RAY-SCATTERING; PROTEIN SECONDARY STRUCTURE; TRIMETHYLAMINE N-OXIDE; SCANNING CALORIMETRY; DENATURED STATES; WATER; TEMPERATURE; HYDRATION; CLASSIFICATION; SIMULATIONS;
Subjects: 500 Science > 570 Life sciences
Divisions: Biology, Preclinical Medicine > Institut für Biophysik und physikalische Biochemie > Prof. Dr. Dr. Hans Robert Kalbitzer
Depositing User: Dr. Gernot Deinzer
Date Deposited: 08 Jul 2020 08:36
Last Modified: 08 Jul 2020 08:36
URI: https://pred.uni-regensburg.de/id/eprint/24017

Actions (login required)

View Item View Item