Contribution of Hydrogen Bonds to the Conformational Stability of Human Lysozyme: Calorimetry and X-ray Analysis of Six Ser → Ala Mutants,
- 29 April 1999
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 38 (20), 6623-6629
- https://doi.org/10.1021/bi9901228
Abstract
To further examine the contribution of hydrogen bonds to the conformational stability of the human lysozyme, six Ser to Ala mutants were constructed. The thermodynamic parameters for denaturation of these six Ser mutant proteins were investigated by differential scanning calorimetry (DSC), and the crystal structures were determined by X-ray analysis. The denaturation Gibbs energy (ΔG) of the Ser mutant proteins was changed from 2.0 to −5.7 kJ/mol, compared to that of the wild-type protein. With an analysis in which some factors that affected the stability due to mutation were considered, the contribution of hydrogen bonds to the stability (ΔΔGHB) was extracted on the basis of the structures of the mutant proteins. The results showed that hydrogen bonds between protein atoms and between a protein atom and a water bound with the protein molecule favorably contribute to the protein stability. The net contribution of one intramolecular hydrogen bond to protein stability (ΔGHB) was 8.9 ± 2.6 kJ/mol on average. However, the contribution to the protein stability of hydrogen bonds between a protein atom and a bound water molecule was smaller than that for a bond between protein atoms.Keywords
This publication has 11 references indexed in Scilit:
- A general rule for the relationship between hydrophobic effect and conformational stability of a protein: stability and structure of a series of hydrophobic mutants of human lysozymeJournal of Molecular Biology, 1998
- Contribution of water molecules in the interior of a protein to the conformational stabilityJournal of Molecular Biology, 1997
- The Structure, Stability, and Folding Process of Amyloidogenic Mutant Human LysozymeThe Journal of Biochemistry, 1996
- Hydrogen bonding stabilizes globular proteinsBiophysical Journal, 1996
- Contribution of Hydrophobic Residues to the Stability of Human Lysozyme: Calorimetric Studies and X-ray Structural Analysis of the Five Isoleucine to Valine MutantsJournal of Molecular Biology, 1995
- Empirical Scale of Side-Chain Conformational Entropy in Protein FoldingJournal of Molecular Biology, 1993
- The molecular surface packageJournal of Molecular Graphics, 1993
- The folding of an enzyme: VI. The folding pathway of barnase: Comparison with theoretical modelsJournal of Molecular Biology, 1992
- A thermodynamic approach to the problem of stabilization of globular protein structure: A calorimetric studyJournal of Molecular Biology, 1974
- Isolation and characterization of human milk lysozymeArchives of Biochemistry and Biophysics, 1969