1gb2

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spinqualitylabelsall models 1gb2, resolution 1.8Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CRYSTAL STRUCTURE OF MUTANT HUMAN LYSOZYME SUBSTITUTED AT THE SURFACE POSITIONS

Contents 1 Overview 2 Disease 3 About this Structure 4 Reference

Overview

To evaluate the contribution of the amino acid residues on the surface of, a protein to its stability, a series of hydrophobic mutant human lysozymes, (Val to Gly, Ala, Leu, Ile, Met, and Phe) modified at three different, positions on the surface, which are located in the alpha-helix (Val 110), the beta-sheet (Val 2), and the loop (Val 74), were constructed. Their, thermodynamic parameters of denaturation and crystal structures were, examined by calorimetry and by X-ray crystallography at 100 K, respectively. Differences in the denaturation Gibbs energy change between, the wild-type and the hydrophobic mutant proteins ranged from 4.6 to -9.6, kJ/mol, 2.7 to -1.5 kJ/mol, and 3.6 to -0.2 kJ/mol at positions 2, 74, and, 110, respectively. The identical substitution at different positions and, different substitutions at the same position resulted in different degrees, of stabilization. Changes in the stability of the mutant proteins could be, evaluated by a unique equation considering the conformational changes due, to the substitutions [Funahashi et al. (1999) Protein Eng. 12, 841-850]., For this calculation, secondary structural propensities were newly, considered. However, some mutant proteins were not adapted to the, equation. The hydration structures around the mutation sites of the, exceptional mutant proteins were affected due to the substitutions. The, stability changes in the exceptional mutant proteins could be explained by, the formation or destruction of the hydration structures. These results, suggest that the hydration structure mediated via hydrogen bonds covering, the protein surface plays an important role in the conformational, stability of the protein.

Disease

Known diseases associated with this structure: Amyloidosis, renal OMIM:[153450], Microphthalmia, syndromic 1 OMIM:[309800]

About this Structure

1GB2 is a Single protein structure of sequence from Homo sapiens with NA as ligand. Active as Lysozyme, with EC number 3.2.1.17 Full crystallographic information is available from OCA.

Reference

Role of surface hydrophobic residues in the conformational stability of human lysozyme at three different positions., Funahashi J, Takano K, Yamagata Y, Yutani K, Biochemistry. 2000 Nov 28;39(47):14448-56. PMID:11087397

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