Multiple role of hydrophobicity of tryptophan-108 in chicken lysozyme: structural stability, saccharide binding ability, and abnormal pKa of glutamic acid-35.


Abstract

Trp108 of chicken lysozyme is in van der Waals contact with Glu35, one of two catalytic carboxyl groups. The role of Trp108 in lysozyme function and stability was investigated by using mutant lysozymes secreted from yeast. By the replacement of Trp108 with less hydrophobic residues, Tyr (W108Y lysozyme) and Gln (W108Q lysozyme), the activity, saccharide binding ability, stability, and pKa of Glu35 were all decreased with a decrease in the hydrophobicity of residue 108. Namely, at pH 5.5 and 40 degrees C, the activities of W108Y and W108Q lysozymes against glycol chitin were 17.3 and 1.6% of that of wild-type lysozyme, and their dissociation constants for the binding of a trimer of N-acetyl-D-glucosamine were 7.4 and 309 times larger than that of wild-type lysozyme, respectively. For the reversible unfolding at pH 3.5 and 30 degrees C, W108Y and W108Q lysozymes were less stable than wild-type lysozyme by 1.4 and 3.6 kcal/mol, respectively. As for the pKa of Glu35, the values for W108Y and W108Q lysozymes were found to be lower than that for wild-type lysozyme by 0.2 and by 0.6 pKa unit, respectively. The pKa of Glu35 in lysozyme was also decreased from 6.1 to 5.4 by the presence of 1-3 M guanidine hydrochloride, or to 5.5 by the substitution of Asn for Asp52, another catalytic carboxyl group. Thus, both the hydrophobicity of Trp108 and the electrostatic interaction with Asp52 are equally responsible for the abnormally high pKa (6.1) of Glu35, compared with that (4.4) of a normal glutamic acid residue.(ABSTRACT TRUNCATED AT 250 WORDS) Study holds ProTherm entries: 1821, 1822, 1823, 1824, 1825, 1826, 1827, 1828, 1829, 1830, 1831, 1832, 1833, 1834, 1835 Extra Details: chicken lysozyme; hydrophobicity; tryptophan; activity;,structural stability; dissociation constant

Submission Details

ID: Bg9FwdwE3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:18 p.m.

Version: 1

Publication Details
Inoue M;Yamada H;Yasukochi T;Kuroki R;Miki T;Horiuchi T;Imoto T,Biochemistry (1992) Multiple role of hydrophobicity of tryptophan-108 in chicken lysozyme: structural stability, saccharide binding ability, and abnormal pKa of glutamic acid-35. PMID:1610799
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
1HHL 1993-05-04T00:00:00+0000 1.9 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
1BQL 1995-02-03T00:00:00+0000 2.6 STRUCTURE OF AN ANTI-HEL FAB FRAGMENT COMPLEXED WITH BOBWHITE QUAIL LYSOZYME
1DKJ 1996-01-10T00:00:00+0000 2.0 BOBWHITE QUAIL LYSOZYME
1DKK 1996-01-10T00:00:00+0000 1.9 BOBWHITE QUAIL LYSOZYME WITH NITRATE
135L 1993-06-10T00:00:00+0000 1.3 X-RAY STRUCTURE OF MONOCLINIC TURKEY EGG LYSOZYME AT 1.3 ANGSTROMS RESOLUTION
1DZB 2000-02-23T00:00:00+0000 2.0 Crystal structure of phage library-derived single-chain Fv fragment 1F9 in complex with turkey egg-white lysozyme

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
92.2 Lysozyme C P00704 LYSC_NUMME
95.2 Lysozyme C P00703 LYSC_MELGA
95.3 Lysozyme C Q7LZT2 LYSC_TRATE
95.3 Lysozyme C P22910 LYSC_CHRAM
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
96.9 Lysozyme C P00699 LYSC_CALCC
96.9 Lysozyme C P00700 LYSC_COLVI
100.0 Lysozyme C P00698 LYSC_CHICK