Effect of an alternative disulfide bond on the structure, stability, and folding of human lysozyme.


Abstract

Human lysozyme has four disulfide bonds, one of which, Cys65-Cys81, is included in a long loop of the beta-domain. A cysteine-scanning mutagenesis in which the position of Cys65 was shifted within a continuous segment from positions 61 to 67, with fixed Cys81, has previously shown that only the mutant W64CC65A, which has a nonnative Cys64-Cys81 disulfide, can be correctly folded and secreted by yeast. Here, using the W64CC65A mutant, we investigated the effects of an alternative disulfide bond on the structure, stability, and folding of human lysozyme using circular dichroism (CD) and fluorescence spectroscopy combined with a stopped-flow technique. Although the mutant is expected to have a different main-chain structure from that of the wild-type protein around the loop region, far- and near-UV CD spectra show that the native state of the mutant has tightly packed side chains and secondary structure similar to that of the wild-type. Guanidine hydrochloride-induced equilibrium unfolding transition of the mutant is reversible, showing high stability and cooperativity of folding. In the kinetic folding reaction, both proteins accumulate a similar burst-phase intermediate having pronounced secondary structure within the dead time of the measurement and fold into the native structure by means of a similar folding mechanism. Both the kinetic refolding and unfolding reactions of the mutant protein are faster than those of the wild-type, but the increase in the unfolding rate is larger than that of the refolding rate. The Gibbs' free-energy diagrams obtained from the kinetic analysis suggest that the structure around the loop region in the beta-domain of human lysozyme is formed after the transition state of folding, and thus, the effect of the alternative disulfide bond on the structure, stability, and folding of human lysozyme appears mainly in the native state. Study holds ProTherm entries: 8034, 8035 Extra Details: disulfide bonds; stability; folding; free-energy

Submission Details

ID: KysLK2rq3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:35 p.m.

Version: 1

Publication Details
Arai M;Hamel P;Kanaya E;Inaka K;Miki K;Kikuchi M;Kuwajima K,Biochemistry (2000) Effect of an alternative disulfide bond on the structure, stability, and folding of human lysozyme. PMID:10727242
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
133L 1993-06-01T00:00:00+0000 1.77 ROLE OF ARG 115 IN THE CATALYTIC ACTION OF HUMAN LYSOZYME. X-RAY STRUCTURE OF HIS 115 AND GLU 115 MUTANTS
134L 1993-06-01T00:00:00+0000 1.77 ROLE OF ARG 115 IN THE CATALYTIC ACTION OF HUMAN LYSOZYME. X-RAY STRUCTURE OF HIS 115 AND GLU 115 MUTANTS
1B5U 1999-01-11T00:00:00+0000 1.8 CONTRIBUTION OF HYDROGEN BONDS TO THE CONFORMATIONAL STABILITY OF HUMAN LYSOZYME: CALORIMETRY AND X-RAY ANALYSIS OF SIX SER->ALA MUTANT
1B5V 1999-01-11T00:00:00+0000 2.17 CONTRIBUTION OF HYDROGEN BONDS TO THE CONFORMATIONAL STABILITY OF HUMAN LYSOZYME: CALORIMETRY AND X-RAY ANALYSIS OF SIX SER->ALA MUTANTS
1B5W 1999-01-11T00:00:00+0000 2.17 CONTRIBUTION OF HYDROGEN BONDS TO THE CONFORMATIONAL STABILITY OF HUMAN LYSOZYME: CALORIMETRY AND X-RAY ANALYSIS OF SIX SER->ALA MUTANTS
1B5X 1999-01-11T00:00:00+0000 2.0 Contribution of hydrogen bonds to the conformational stability of human lysozyme: calorimetry and x-ray analysis of six ser->ala mutants
1B5Y 1999-01-11T00:00:00+0000 2.2 CONTRIBUTION OF HYDROGEN BONDS TO THE CONFORMATIONAL STABILITY OF HUMAN LYSOZYME: CALORIMETRY AND X-RAY ANALYSIS OF SIX SER->ALA MUTANTS
1B5Z 1999-01-11T00:00:00+0000 2.2 CONTRIBUTION OF HYDROGEN BONDS TO THE CONFORMATIONAL STABILITY OF HUMAN LYSOZYME: CALORIMETRY AND X-RAY ANALYSIS OF SIX SER->ALA MUTANTS
1B7L 1999-01-24T00:00:00+0000 1.8 VERIFICATION OF SPMP USING MUTANT HUMAN LYSOZYMES
1B7M 1999-01-24T00:00:00+0000 2.2 VERIFICATION OF SPMP USING MUTANT HUMAN LYSOZYMES

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
96.9 Lysozyme C P79180 LYSC_HYLLA
99.2 Lysozyme C P79239 LYSC_PONPY
100.0 Lysozyme C P79179 LYSC_GORGO
100.0 Lysozyme C P61628 LYSC_PANTR
100.0 Lysozyme C P61627 LYSC_PANPA
100.0 Lysozyme C P61626 LYSC_HUMAN