Low-temperature unfolding of a mutant of phage T4 lysozyme. 1. Equilibrium studies.


The mutant protein I3C-C97/C54T of phage T4 lysozyme is free of sulfhydryl groups and has a genetically engineered disulfide bridge between positions 3 and 97 (Perry & Wetzel, 1986). This protein has a maximum stability at 12 degrees C in 3 M guanidinium chloride and undergoes reversible high- and low-temperature melting at 28 and -3 degrees C, respectively, in this medium. The free energy of stabilization of the protein has been studied over a range of temperature that includes both melting transitions. The stability curve fits a constant delta Cp model over the entire range, permitting an unusually complete determination of the thermodynamic parameters of the protein and demonstrating that the low-temperature unfolded form of the protein may be interpreted as an extrapolation with constant delta Cp of the high-temperature unfolded form. The free energy of unfolding is a linear function of guanidinium concentration within experimental error which permits a rough estimate of the stability of the protein at low temperatures and of the differential interaction of the unfolded protein with guanidinium chloride. These equilibrium studies provide a basis for the interpretation of the kinetic studies reported in the following paper. Study holds ProTherm entries: 3831, 3832, 3833, 3834 Extra Details: low-temperature unfolding; equilibrium studies;,stability curve; constant delta Cp model

Submission Details

ID: 2Nq7CpSt

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:22 p.m.

Version: 1

Publication Details
Chen BL;Schellman JA,Biochemistry (1989) Low-temperature unfolding of a mutant of phage T4 lysozyme. 1. Equilibrium studies. PMID:2653427
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
3EML 2008-09-24T00:00:00+0000 2.6 The 2.6 A Crystal Structure of a Human A2A Adenosine Receptor bound to ZM241385.
3SB8 2011-06-03T00:00:00+0000 2.65 Cu-mediated Dimer of T4 Lysozyme D61H/K65H by Synthetic Symmetrization
5JWW 2016-05-12T00:00:00+0000 1.47 T4 Lysozyme L99A/M102Q with 1-Hydro-2-ethyl-1,2-azaborine Bound
3SB9 2011-06-03T00:00:00+0000 2.45 Cu-mediated Dimer of T4 Lysozyme R76H/R80H by Synthetic Symmetrization
5YQR 2017-11-07T00:00:00+0000 2.4 Crystal structure of the PH-like domain of Lam6
1CTW 1999-08-20T00:00:00+0000 2.1 T4 LYSOZYME MUTANT I78A
3SN6 2011-06-28T00:00:00+0000 3.2 Crystal structure of the beta2 adrenergic receptor-Gs protein complex
2RBQ 2007-09-19T00:00:00+0000 1.63 3-methylbenzylazide in complex with T4 L99A/M102Q
1T8F 2004-05-12T00:00:00+0000 2.15 Crystal structure of phage T4 lysozyme mutant R14A/K16A/I17A/K19A/T21A/E22A/C54T/C97A
3CDV 2008-02-27T00:00:00+0000 1.73 Contributions of all 20 amino acids at site 96 to the stability and structure of T4 lysozyme

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Endolysin P00720 ENLYS_BPT4