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
ID: 2Nq7CpSt
Submitter: Connie Wang
Submission Date: April 24, 2018, 8:22 p.m.
Version: 1
Colors: | D | E | R | H | K | S | T | N | Q | A | V | I | L | M | F | Y | W | C | G | P |
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Structure ID | Release Date | Resolution | Structure Title |
---|---|---|---|
102L | 1992-09-29T00:00:00+0000 | 1.74 | HOW AMINO-ACID INSERTIONS ARE ALLOWED IN AN ALPHA-HELIX OF T4 LYSOZYME |
103L | 1992-09-29T00:00:00+0000 | 1.9 | HOW AMINO-ACID INSERTIONS ARE ALLOWED IN AN ALPHA-HELIX OF T4 LYSOZYME |
104L | 1992-09-29T00:00:00+0000 | 2.8 | HOW AMINO-ACID INSERTIONS ARE ALLOWED IN AN ALPHA-HELIX OF T4 LYSOZYME |
107L | 1992-12-17T00:00:00+0000 | 1.8 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
108L | 1992-12-17T00:00:00+0000 | 1.8 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
109L | 1992-12-17T00:00:00+0000 | 1.85 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
110L | 1992-12-17T00:00:00+0000 | 1.7 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
111L | 1992-12-17T00:00:00+0000 | 1.8 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
112L | 1992-12-17T00:00:00+0000 | 1.8 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
113L | 1992-12-17T00:00:00+0000 | 1.8 | STRUCTURAL BASIS OF ALPHA-HELIX PROPENSITY AT TWO SITES IN T4 LYSOZYME |
Percent Identity | Matching Chains | Protein | Accession | Entry Name |
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100.0 | Endolysin | P00720 | ENLYS_BPT4 |