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 UniProtKB Entries

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