Thermal stability determinants of chicken egg-white lysozyme core mutants: hydrophobicity, packing volume, and conserved buried water molecules.


Abstract

A series of 24 mutants was made in the buried core of chicken lysozyme at positions 40, 55, and 91. The midpoint temperature of thermal denaturation transition (Tm) values of these core constructs range from 60.9 to 77.3 degrees C, extending an earlier, more limited investigation on thermostability. The Tm values of variants containing conservative replacements for the wild type (WT) (Thr 40-Ile 55-Ser 91) triplet are linearly correlated with hydrophobicity (r = 0.81) and, to a lesser degree, with combined side-chain volume (r = 0.75). The X-ray structures of the S91A (1.9 A) and I55L/S91T/D101S (1.7 A) mutants are presented. The former amino acid change is found in duck and mammalian lysozymes, and the latter contains the most thermostable core triplet. A network of four conserved, buried water molecules is associated with the core. It is postulated that these water molecules significantly influence the mutational tolerance at the individual triplet positions. The pH dependence of Tm for the S91D mutant was compared with that of WT enzyme. The pKa of S91D is 1.2 units higher in the native than in the denatured state, corresponding to delta delta G298 = 1.7 kcal/mol. This is a low value for charge burial and likely reflects the moderating influence of the buried water molecules or a conformational change. Thermal and chemical denaturation and far UV CD spectroscopy were used to characterize the in vitro properties of I55T. This variant, which buries a hydroxyl group, has similar properties to those of the human amyloidogenic variant I56T. Study holds ProTherm entries: 1795, 1796, 1797, 1798, 1799, 1800, 1801, 1802, 1803, 1804, 1805, 1806, 1807, 1808, 1809, 1810, 1811, 1812, 1813, 1814, 1815, 1816, 1817, 1818, 1819, 1820, 13890, 13891, 13892, 13893, 13894, 13895, 13896, 13897, 13898, 13899, 13900, 13901, 13902, 13903, 13904, 13905, 13906, 13907, 13908, 13909, 13910, 13911, 13912, 13913 Extra Details: buried water; chicken lysozyme; hydrophobicity; internal packing;,site-directed mutagenesis; X-ray structure; thermal stability;

Submission Details

ID: anQDUU3h3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:17 p.m.

Version: 1

Publication Details
Shih P;Holland DR;Kirsch JF,Protein Sci. (1995) Thermal stability determinants of chicken egg-white lysozyme core mutants: hydrophobicity, packing volume, and conserved buried water molecules. PMID:8535241
Additional Information

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P
 

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)


Relevant PDB Entries

Structure ID Release Date Resolution Structure Title
2IHL 1993-06-29T00:00:00+0000 1.4 LYSOZYME (E.C.3.2.1.17) (JAPANESE QUAIL)
1FBI 1995-01-19T00:00:00+0000 3.0 CRYSTAL STRUCTURE OF A CROSS-REACTION COMPLEX BETWEEN FAB F9.13.7 AND GUINEA-FOWL LYSOZYME
1GHL 1993-05-04T00:00:00+0000 2.1 THE THREE-DIMENSIONAL STRUCTURE OF PHEASANT AND GUINEA-FOWL EGG LYSOZYMES
1JHL 1993-05-04T00:00:00+0000 2.4 THREE-DIMENSIONAL STRUCTURE OF A HETEROCLITIC ANTIGEN-ANTIBODY CROSS-REACTION COMPLEX
1HHL 1993-05-04T00:00:00+0000 1.9 THE THREE-DIMENSIONAL STRUCTURE OF PHEASANT AND GUINEA-FOWL EGG LYSOZYMES
1BQL 1995-02-03T00:00:00+0000 2.6 STRUCTURE OF AN ANTI-HEL FAB FRAGMENT COMPLEXED WITH BOBWHITE QUAIL LYSOZYME
1DKK 1996-01-10T00:00:00+0000 1.9 BOBWHITE QUAIL LYSOZYME WITH NITRATE
1DKJ 1996-01-10T00:00:00+0000 2.0 BOBWHITE QUAIL LYSOZYME
1JTP 2001-08-21T00:00:00+0000 1.9 Degenerate interfaces in antigen-antibody complexes
3LZ2 1991-09-13T00:00:00+0000 2.5 STRUCTURE DETERMINATION OF TURKEY EGG WHITE LYSOZYME USING LAUE DIFFRACTION

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
92.3 Lysozyme C P49663 LYSC_PHAVE
93.0 Lysozyme C P81711 LYSC_SYRSO
93.2 Lysozyme C P00702 LYSC_PHACO
94.6 Lysozyme C P24533 LYSC_SYRRE
93.0 Lysozyme C P24364 LYSC_LOPLE
95.2 Lysozyme C P00703 LYSC_MELGA
95.3 Lysozyme C Q7LZT2 LYSC_TRATE
95.3 Lysozyme C P22910 LYSC_CHRAM
94.6 Lysozyme C P00704 LYSC_NUMME
96.1 Lysozyme C P19849 LYSC_PAVCR
95.3 Lysozyme C P00701 LYSC_COTJA
96.1 Lysozyme C Q7LZI3 LYSC_TRASA
96.9 Lysozyme C Q7LZP9 LYSC_LOPIM
96.9 Lysozyme C Q7LZQ0 LYSC_CATWA
99.2 Lysozyme C P00699 LYSC_CALCC
99.2 Lysozyme C P00700 LYSC_COLVI
100.0 Lysozyme C P00698 LYSC_CHICK