Sucrose reduces the efficiency of protein denaturation by a chaotropic agent.


Sugars and polyols are used to stabilize proteins. The degree of stabilization conferred on a model protein by sucrose was calculated in terms of the free energy of folding. Phosphoglycerate kinase (PGK) was denatured by guanidine hydrochloride (GuHCl) in different sucrose concentrations. The linear extrapolation method [1,2] was used to calculate the free energy of folding in the absence of denaturant. Although sucrose increased the concentration of GuHCl required to unfold the protein, the free energy of folding in water was unchanged. In order to probe the nature of the stabilizing effect of sucrose, an FT-Raman spectroscopic study of denaturant-polyol systems was undertaken. Investigations of interactions between GuHCl, urea or formamide and polyhydric compounds, revealed no evidence for hydrogen bonding or dipole-dipole associations. Polyhydric compounds caused minor changes in denaturant spectra although the converse was not observed. The structure of deuterated water changed on addition of denaturants. For non-ionic denaturants, addition of polyhydric solutes countered this change in water structure. Thus polyhydric compounds oppose the effect of denaturants on water structure. The observed increase in GuHCl concentration required to unfold PGK in the presence of sucrose may be attributed to this property of sucrose. Study holds ProTherm entries: 9340 Extra Details: dithiothreitol(2 mM) was added in the experiment

Submission Details

ID: c6jvFy864

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:37 p.m.

Version: 1

Publication Details
Taylor LS;York P;Williams AC;Edwards HG;Mehta V;Jackson GS;Badcoe IG;Clarke AR,Biochim. Biophys. Acta (1995) Sucrose reduces the efficiency of protein denaturation by a chaotropic agent. PMID:7492597
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 UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Phosphoglycerate kinase P18912 PGK_GEOSE
98.2 Phosphoglycerate kinase Q5KVE4 PGK_GEOKA
90.1 Phosphoglycerate kinase C5D7M4 PGK_GEOSW