Thermal unfolding of staphylococcal nuclease and several mutant forms thereof studied by differential scanning calorimetry

Akiyoshi Tanaka, Julian M. Sturtevant, John Flanagan

Research output: Contribution to journalArticle

45 Citations (Scopus)

Abstract

The effects of eight mutations on the thermodynamics of the reversible thermal unfolding of staphylococcal nuclease have been determined over a range of pH and protein concentration by means of differential scanning calorimetry. Variation of the protein concentration was included in our study because we found a significant dependence of the thermodynamics of protein unfolding on concentration. Values for the change in the standard free energy of unfolding, ΔΔGd 0, produced by the mutations in the pH range 5.0–7.0 varied from 1.9 kcal mol−1 (apparent stabilization) for H124L to ‐2.8 kcal mol−1 (apparent destabilization) for L25A. As has been observed in numerous other cases, there is no correlation in magnitude or sign between ΔΔGd 0 and the corresponding values for ΔΔHd and TΔΔSd 0, the latter quantities being in most cases much larger in magnitude than ΔΔGd 0. This fact emphasizes the difficulty in attempting to correlate the thermodynamic changes with structural changes observed by X‐ray crystallography.

Original languageEnglish (US)
Pages (from-to)567-576
Number of pages10
JournalProtein Science
Volume2
Issue number4
DOIs
StatePublished - Jan 1 1993

Fingerprint

Micrococcal Nuclease
Differential Scanning Calorimetry
Thermodynamics
Differential scanning calorimetry
Hot Temperature
Protein Unfolding
Mutation
Proteins
Crystallography
X Ray Crystallography
Free energy
Stabilization

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Molecular Biology

Cite this

@article{3ed0be35152c4cb4aa9e4ac0c208a0be,
title = "Thermal unfolding of staphylococcal nuclease and several mutant forms thereof studied by differential scanning calorimetry",
abstract = "The effects of eight mutations on the thermodynamics of the reversible thermal unfolding of staphylococcal nuclease have been determined over a range of pH and protein concentration by means of differential scanning calorimetry. Variation of the protein concentration was included in our study because we found a significant dependence of the thermodynamics of protein unfolding on concentration. Values for the change in the standard free energy of unfolding, ΔΔGd 0, produced by the mutations in the pH range 5.0–7.0 varied from 1.9 kcal mol−1 (apparent stabilization) for H124L to ‐2.8 kcal mol−1 (apparent destabilization) for L25A. As has been observed in numerous other cases, there is no correlation in magnitude or sign between ΔΔGd 0 and the corresponding values for ΔΔHd and TΔΔSd 0, the latter quantities being in most cases much larger in magnitude than ΔΔGd 0. This fact emphasizes the difficulty in attempting to correlate the thermodynamic changes with structural changes observed by X‐ray crystallography.",
author = "Akiyoshi Tanaka and Sturtevant, {Julian M.} and John Flanagan",
year = "1993",
month = "1",
day = "1",
doi = "10.1002/pro.5560020408",
language = "English (US)",
volume = "2",
pages = "567--576",
journal = "Protein Science",
issn = "0961-8368",
publisher = "Cold Spring Harbor Laboratory Press",
number = "4",

}

Thermal unfolding of staphylococcal nuclease and several mutant forms thereof studied by differential scanning calorimetry. / Tanaka, Akiyoshi; Sturtevant, Julian M.; Flanagan, John.

In: Protein Science, Vol. 2, No. 4, 01.01.1993, p. 567-576.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Thermal unfolding of staphylococcal nuclease and several mutant forms thereof studied by differential scanning calorimetry

AU - Tanaka, Akiyoshi

AU - Sturtevant, Julian M.

AU - Flanagan, John

PY - 1993/1/1

Y1 - 1993/1/1

N2 - The effects of eight mutations on the thermodynamics of the reversible thermal unfolding of staphylococcal nuclease have been determined over a range of pH and protein concentration by means of differential scanning calorimetry. Variation of the protein concentration was included in our study because we found a significant dependence of the thermodynamics of protein unfolding on concentration. Values for the change in the standard free energy of unfolding, ΔΔGd 0, produced by the mutations in the pH range 5.0–7.0 varied from 1.9 kcal mol−1 (apparent stabilization) for H124L to ‐2.8 kcal mol−1 (apparent destabilization) for L25A. As has been observed in numerous other cases, there is no correlation in magnitude or sign between ΔΔGd 0 and the corresponding values for ΔΔHd and TΔΔSd 0, the latter quantities being in most cases much larger in magnitude than ΔΔGd 0. This fact emphasizes the difficulty in attempting to correlate the thermodynamic changes with structural changes observed by X‐ray crystallography.

AB - The effects of eight mutations on the thermodynamics of the reversible thermal unfolding of staphylococcal nuclease have been determined over a range of pH and protein concentration by means of differential scanning calorimetry. Variation of the protein concentration was included in our study because we found a significant dependence of the thermodynamics of protein unfolding on concentration. Values for the change in the standard free energy of unfolding, ΔΔGd 0, produced by the mutations in the pH range 5.0–7.0 varied from 1.9 kcal mol−1 (apparent stabilization) for H124L to ‐2.8 kcal mol−1 (apparent destabilization) for L25A. As has been observed in numerous other cases, there is no correlation in magnitude or sign between ΔΔGd 0 and the corresponding values for ΔΔHd and TΔΔSd 0, the latter quantities being in most cases much larger in magnitude than ΔΔGd 0. This fact emphasizes the difficulty in attempting to correlate the thermodynamic changes with structural changes observed by X‐ray crystallography.

UR - http://www.scopus.com/inward/record.url?scp=0027469674&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0027469674&partnerID=8YFLogxK

U2 - 10.1002/pro.5560020408

DO - 10.1002/pro.5560020408

M3 - Article

VL - 2

SP - 567

EP - 576

JO - Protein Science

JF - Protein Science

SN - 0961-8368

IS - 4

ER -