Contribution of amino acid substitutions at two different interior positions to the conformational stability of human lysozyme

• DOI: 10.1093/protein/12.10.841
• Publication Date: 2002-07-26T22:32:47Z
• Authors: Jun Funahashi; Kazufumi Takano; Yuriko Yamagata; Katsuhide Yutani
• Keywords: Denaturation (fissile materials); Conformational entropy

To elucidate correlative relationships between structural change and thermodynamic stability in proteins, a series of mutant human lysozymes modified at two buried positions (Ile56 Ile59) were examined. Their parameters denaturation crystal structures studied by calorimetry X-ray crystallography. The mutants 56 59 exhibited different responses to amino acid substitutions. changes due substitutions showed linear correlation with hydrophobicity substituted residues, having slopes each mutation site. However, the was found be represented unique equation involving physical properties calculated from structures. By fitting present previous data for various equation, magnitudes carbon atom nitrogen neutral oxygen atoms 0.178 –0.013 kJ/mol.Å2, respectively. It also that contribution hydrogen bond length 3.0 Å protein 5.1 kJ/mol entropy loss newly introduction water molecules 7.8 kJ/mol.