Conformational stability of bovine holo and apo adrenodoxin--a scanning calorimetric study.


Holo and apo adrenodoxin were studied by differential scanning calorimetry, absorption spectroscopy, limited proteolysis, and size-exclusion chromatography. To determine the conformational stability of adrenodoxin, a method was found that prevents the irreversible destruction of the iron-sulfur center. The approach makes use of a buffer solution that contains sodium sulfide and mercaptoethanol. The thermal transition of adrenodoxin takes place at Ttrs = 46-57 degrees C, depending on the Na2S concentration with a denaturation enthalpy of delta H = 300-380 kJ/mol. From delta H versus Ttrs a heat capacity change was determined as delta Cp = 7.5 +/- 1.2 kJ/mol/K. The apo protein is less stable than the holo protein as judged by the lower denaturation enthalpy (delta H = 93 +/- 14 kJ/mol at Ttrs = 37.4 +/- 3.3 degrees C) and the higher proteolytic susceptibility. The importance of the iron-sulfur cluster for the conformational stability of adrenodoxin and some conditions for refolding of the thermally denatured protein are discussed. Study holds ProTherm entries: 7246, 7247, 7248, 7249, 7250, 7251 Extra Details: Na2S(10 mM) and ascorbic acid(1 mM) were added in the experiment ferredoxin; iron-sulfur protein; protein unfolding;,scanning microcalorimetry; thermodynamics

Submission Details

ID: czRsAPJd

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:33 p.m.

Version: 1

Publication Details
Burova TV;Bernhardt R;Pfeil W,Protein Sci. (1995) Conformational stability of bovine holo and apo adrenodoxin--a scanning calorimetric study. PMID:7663346
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
3N9Y 2010-05-31T00:00:00+0000 2.1 Crystal structure of human CYP11A1 in complex with cholesterol
3N9Z 2010-05-31T00:00:00+0000 2.17 Crystal structure of human CYP11A1 in complex with 22-hydroxycholesterol
3NA0 2010-05-31T00:00:00+0000 2.5 Crystal structure of human CYP11A1 in complex with 20,22-dihydroxycholesterol
3NA1 2010-05-31T00:00:00+0000 2.25 Crystal structure of human CYP11A1 in complex with 20-hydroxycholesterol
3P1M 2010-09-30T00:00:00+0000 2.54 Crystal structure of human ferredoxin-1 (FDX1) in complex with iron-sulfur cluster
7M8I 2021-03-29T00:00:00+0000 2.94 Human CYP11B2 and human adrenodoxin in complex with fadrozole
1AYF 1997-11-03T00:00:00+0000 1.85 BOVINE ADRENODOXIN (OXIDIZED)
1CJE 1999-04-12T00:00:00+0000 2.5 ADRENODOXIN FROM BOVINE

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
92.4 Adrenodoxin, mitochondrial P46656 ADX_MOUSE
94.3 Adrenodoxin, mitochondrial P00258 ADX_PIG
94.3 Adrenodoxin, mitochondrial P10109 ADX_HUMAN
96.1 Adrenodoxin, mitochondrial P29330 ADX_SHEEP
100.0 Adrenodoxin, mitochondrial P00257 ADX_BOVIN