Studies of Pseudomonas aeruginosa azurin mutants: cavities in beta-barrel do not affect refolding speed.


Abstract

Pseudomonas aeruginosa azurin is a blue-copper protein with a Greek-key fold. Removal of copper produces an apoprotein with the same structure as holoazurin. To address the effects on thermodynamic stability and folding dynamics caused by small cavities in a beta-barrel, we have studied the behavior of the apo-forms of wild-type and two mutant (His-46-Gly and His-117-Gly) azurins. The equilibrium- and kinetic-folding and unfolding reactions appear as two-state processes for all three proteins. The thermodynamic stability of the two mutants is significantly decreased as compared with the stability of wild-type azurin, in accord with cavities in or near the hydrophobic interior having an overall destabilizing effect. Large differences are also found in the unfolding rates: the mutants unfold much faster than wild-type azurin. In contrast, the folding-rate constants are almost identical for the three proteins and closely match the rate-constant predicted from the native-state topology of azurin. We conclude that the topology is more important than equilibrium stability in determining the folding speed of azurin. Study holds ProTherm entries: 13085, 13086, 13087 Extra Details: blue-copper protein; beta-barrel; rate constant; two-state process

Submission Details

ID: Fboyx9hY3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:44 p.m.

Version: 1

Publication Details
Pozdnyakova I;Guidry J;Wittung-Stafshede P,Biophys. J. (2002) Studies of Pseudomonas aeruginosa azurin mutants: cavities in beta-barrel do not affect refolding speed. PMID:11964251
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
1AG0 1997-03-26T00:00:00+0000 2.4 STRUCTURE OF CYS 112 ASP AZURIN FROM PSEUDOMONAS AERUGINOSA
1AZN 1994-05-27T00:00:00+0000 2.6 CRYSTAL STRUCTURE OF THE AZURIN MUTANT PHE114ALA FROM PSEUDOMONAS AERUGINOSA AT 2.6 ANGSTROMS RESOLUTION
1AZR 1993-03-04T00:00:00+0000 2.4 CRYSTAL STRUCTURE OF PSEUDOMONAS AERUGINOSA ZINC AZURIN MUTANT ASP47ASP AT 2.4 ANGSTROMS RESOLUTION
1AZU 1980-08-04T00:00:00+0000 2.7 STRUCTURAL FEATURES OF AZURIN AT 2.7 ANGSTROMS RESOLUTION
1BEX 1998-05-18T00:00:00+0000 2.3 STRUCTURE OF RUTHENIUM-MODIFIED PSEUDOMONAS AERUGINOSA AZURIN
1CC3 1999-03-03T00:00:00+0000 1.65 PURPLE CUA CENTER
1E5Y 2000-08-04T00:00:00+0000 2.0 Azurin from Pseudomonas aeruginosa, reduced form, pH 5.5
1E5Z 2000-08-04T00:00:00+0000 2.0 Azurin from Pseudomonas aeruginosa, reduced form, pH 9.0
1E65 2000-08-08T00:00:00+0000 1.85 Azurin from Pseudomonas aeruginosa, apo form
1E67 2000-08-09T00:00:00+0000 2.14 Zn-Azurin from Pseudomonas aeruginosa

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
99.2 Azurin B3EWN9 AZUR_PSEAI
100.0 Azurin P00282 AZUR_PSEAE