Comparison of the conformational stability of the molten globule and native states of horse cytochrome c. Effects of acetylation, heat, urea and guanidine-hydrochloride.


Abstract

The molten globule state has been assumed to be a major intermediate of protein folding. We compared the stability of the native and acidic molten globule states of horse ferricytochrome c against heat, urea and guanidine hydrochloride (Gdn-HCl) using the intact species and species modified by various degrees of acetylation of the lysyl epsilon-amino groups. After acetylation, the amino groups cannot protonate at acidic pH. Thermal and urea-induced unfolding transitions measured by far-UV circular dichroism and differential scanning calorimetry showed that, whereas acetylation stabilizes the molten globule state at pH 2, it destabilizes the native state at pH 7, suggesting a difference in their mechanisms of conformational stability. On the other hand, the effects of Gdn-Hcl were remarkable. Contrary to what was expected from the thermal and urea-induced unfolding transitions, the Gdn-HCl-induced unfolding transition of the native state at pH 7 was insensitive to the extent of acetylation. At pH 2, Gdn-HCl at low concentrations stabilized the molten globule state and, at high concentrations, destabilized it. Consideration of the difference in the effects of Gdn-HCl from those of urea or heat indicated that, whereas the net positive charge repulsion destabilizes the molten globule state at pH 2, the local negative charge repulsion produced by acetylation of amino groups, and not the net charge, critically destabilizes the native state at pH 7. These results predict that, because of its ionic nature, Gdn-HCl will produce substantially different effects on the conformational states of some proteins compared with those of urea. Study holds ProTherm entries: 10021 Extra Details: cytochrome c; molten globule; denaturation; electrostatics

Submission Details

ID: ytem6tNV3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:39 p.m.

Version: 1

Publication Details
Hagihara Y;Tan Y;Goto Y,J. Mol. Biol. (1994) Comparison of the conformational stability of the molten globule and native states of horse cytochrome c. Effects of acetylation, heat, urea and guanidine-hydrochloride. PMID:8145245
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 Cytochrome c P00004 CYC_HORSE
99.0 Cytochrome c P68097 CYC_EQUAS
99.0 Cytochrome c P68096 CYC_EQUBU
97.1 Cytochrome c P62894 CYC_BOVIN
97.1 Cytochrome c P62895 CYC_PIG
97.1 Cytochrome c P62896 CYC_SHEEP
94.3 Cytochrome c P00007 CYC_HIPAM
95.2 Cytochrome c P68099 CYC_CAMDR
95.2 Cytochrome c P68100 CYC_ESCRO
95.2 Cytochrome c P68098 CYC_LAMGU
94.3 Cytochrome c P62897 CYC_MOUSE
94.3 Cytochrome c P00008 CYC_RABIT
94.3 Cytochrome c P62898 CYC_RAT
94.3 Cytochrome c P00011 CYC_CANLF
93.3 Cytochrome c P00014 CYC_MACGI
93.3 Cytochrome c P00013 CYC_MINSC
93.3 Cytochrome c Q52V09 CYC_CEPBA
93.3 Cytochrome c P00012 CYC_MIRLE
90.5 Cytochrome c Q52V10 CYC_SAISC
92.3 Cytochrome c P81280 CYC_ALLMI
92.2 Cytochrome c P00020 CYC_ANAPL
91.3 Cytochrome c P00021 CYC_COLLI
90.3 Cytochrome c B4USV4 CYC_OTOGA