The peculiar nature of the guanidine hydrochloride-induced two-state denaturation of staphylococcal nuclease: a calorimetric study.


Abstract

This work determines the ratio of DeltaH(vH) /DeltaH(cal) for staphylococcal nuclease (SN) denaturation in guanidine hydrochloride (GdnHCl) to test whether GdnHCl-induced denaturation is two-state. Heats of mixing of SN as a function of [GdnHCl] were determined at pH 7.0 and 25 degrees C. The resulting plot of DeltaH(mix) vs [GdnHCl] exhibits a sigmoid shaped curve with linear pre- and post-denaturational base lines. Extending the pre- and post-denaturational lines to zero [GdnHCl] gives a calorimetric DeltaH (DeltaH(cal)) of 24.1 +/- 1.0 kcal/mol, for SN denaturation in the limit of zero GdnHCl concentration. Guanidine hydrochloride-induced denaturation Gibbs energy changes in the limit of zero denaturant concentration (DeltaG degrees (N)(-)(D)) at pH 7. 0 were determined for SN from fluorescence measurements at fixed temperatures over the range from 15 to 35 degrees C. Analysis of the resulting temperature-dependent DeltaG degrees (N)(-)(D) data defines a van't Hoff denaturation enthalpy change (DeltaH(vH)) of 26. 4 +/- 2.8 kcal/mol. The model-dependent van't Hoff DeltaH(vH) divided by the model-independent DeltaH(cal) gives a ratio of 1.1 +/- 0.1 for DeltaH(vH)/DeltaH(cal), a result that rules out the presence of thermodynamically important intermediate states in the GdnHCl-induced denaturation of SN. The likelihood that GdnHCl-induced SN denaturation involves a special type of two-state denaturation, known as a variable two-state process, is discussed in terms of the thermodynamic implications of the process. Study holds ProTherm entries: 6547, 6548, 6549, 6550, 6551, 6552, 6553 Extra Details: hydrochloride-induced denaturation; temperature-dependent;,enthalpy change; two-state denaturation

Submission Details

ID: yQn47vJt

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:32 p.m.

Version: 1

Publication Details
Yang M;Liu D;Bolen DW,Biochemistry (1999) The peculiar nature of the guanidine hydrochloride-induced two-state denaturation of staphylococcal nuclease: a calorimetric study. PMID:10460179
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
4WRD 2014-10-23T00:00:00+0000 1.65 Crystal structure of Staphylcoccal nulease variant Delta+PHS V66E L125E at cryogenic temperature
2LKV 2011-10-21T00:00:00+0000 0 Staphylococcal Nuclease PHS variant
2M00 2012-10-14T00:00:00+0000 0 Solution structure of staphylococcal nuclease E43S mutant in the presence of ssDNA and Cd2+
2OXP 2007-02-20T00:00:00+0000 2.0 Crystal Structure of Staphylococcal Nuclease mutant V66D/P117G/H124L/S128A
3D4W 2008-05-15T00:00:00+0000 1.9 Crystal structure of Staphylococcal nuclease variant Delta+PHS A109R at cryogenic temperature
3D8G 2008-05-23T00:00:00+0000 1.99 Crystal structure of Staphylococcal nuclease variant Delta+PHS I72R at cryogenic temperature
3MVV 2010-05-04T00:00:00+0000 1.72 Crystal structure of Staphylococcal nuclease variant Delta+PHS F34A at cryogenic temperature
3QOJ 2011-02-10T00:00:00+0000 1.6 Cryogenic structure of Staphylococcal nuclease variant D+PHS/V23K
3QOL 2011-02-10T00:00:00+0000 1.9 Crystal structure of Staphylococcal nuclease variant D+PHS/V23E at pH 6 determined at 100 K
3R3O 2011-03-16T00:00:00+0000 1.9 Crystal structure of Staphylococcal nuclease variant Delta+PHS T62A at cryogenic temperature and with high redundancy

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
99.3 Thermonuclease Q6GIK1 NUC_STAAR
99.3 Thermonuclease Q8NXI6 NUC_STAAW
99.3 Thermonuclease Q6GB41 NUC_STAAS
99.1 Thermonuclease Q7A6P2 NUC_STAAN
99.1 Thermonuclease Q99VJ0 NUC_STAAM
99.3 Thermonuclease Q5HHM4 NUC_STAAC
100.0 Thermonuclease P00644 NUC_STAAU