Breakdown in the relationship between thermal and thermodynamic stability in an interleukin-1 beta point mutant modified in a surface loop.


Abstract

Sequence variants of the beta-barrel protein interleukin-1 beta have been analyzed for their stabilities toward irreversible thermal inactivation by monitoring the generation of light scattering aggregates on heating. The derived temperatures for the onset of aggregation (T(agg) values) correlate well with the free energies of unfolding of these proteins with the exception of one variant, Lys97-->Val (K97V), which undergoes aggregation at a temperature 7 degrees C lower than expected based on its thermodynamic stability. This lower than expected thermal stability may be due to generation of an aggregation-prone unfolding intermediate at a temperature lower than the Tm of the global transition. This hypothesis is supported by the location of residue 97 in the long 86-99 loop which has structural features suggesting it may comprise a small, independent folding unit or microdomain. The excellent correlation of thermal and thermodynamic stabilities of seven of the eight variants tested is consistent with accepted models for thermal inactivation of proteins. At the same time the poor fit of the K97V variant underscores the risk in using thermal stability data in quantitative analysis of mutational studies of the folding stability of proteins.

Submission Details

ID: T35CrH3W4

Submitter: Shu-Ching Ou

Submission Date: Oct. 23, 2018, 2:27 p.m.

Version: 1

Publication Details
Chrunyk BA;Wetzel R,Protein Eng (1993) Breakdown in the relationship between thermal and thermodynamic stability in an interleukin-1 beta point mutant modified in a surface loop. PMID:8248096
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
1HIB 1993-03-29T00:00:00+0000 2.4 THE STRUCTURE OF AN INTERLEUKIN-1 BETA MUTANT WITH REDUCED BIOACTIVITY SHOWS MULTIPLE SUBTLE CHANGES IN CONFORMATION THAT AFFECT PROTEIN-PROTEIN RECOGNITION
1I1B 1989-12-05T00:00:00+0000 2.0 CRYSTAL STRUCTURE OF RECOMBINANT HUMAN INTERLEUKIN-1BETA AT 2.0 ANGSTROMS RESOLUTION
1IOB 1996-03-14T00:00:00+0000 2.0 INTERLEUKIN-1 BETA FROM JOINT X-RAY AND NMR REFINEMENT
1ITB 1997-01-15T00:00:00+0000 2.5 TYPE-1 INTERLEUKIN-1 RECEPTOR COMPLEXED WITH INTERLEUKIN-1 BETA
1L2H 2002-02-21T00:00:00+0000 1.54 Crystal structure of Interleukin 1-beta F42W/W120F mutant
1S0L 2003-12-31T00:00:00+0000 2.34 Interleukin 1 beta mutant F42W
1T4Q 2004-04-30T00:00:00+0000 2.1 Interleukin 1 beta F101W
1TOO 2004-06-14T00:00:00+0000 2.1 Interleukin 1B Mutant F146W
1TP0 2004-06-15T00:00:00+0000 2.2 Triple mutation in interleukin 1 beta cavity:replacement of phenylalanines with tryptophan.
1TWE 2004-06-30T00:00:00+0000 2.1 INTERLEUKIN 1 BETA MUTANT F101Y

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
94.8 Interleukin-1 beta P46648 IL1B_CERAT
95.4 Interleukin-1 beta P79182 IL1B_MACFA
95.4 Interleukin-1 beta P51493 IL1B_MACNE
96.1 Interleukin-1 beta P48090 IL1B_MACMU
100.0 Interleukin-1 beta P01584 IL1B_HUMAN