Role of intramolecular disulfides in stability and structure of a noncovalent homodimer.


Abstract

The importance of intramolecular disulfides in a noncovalent dimeric protein interleukin-8 (IL-8) has been studied by replacing cysteines in each of the two disulfide pairs with alpha-aminobutyric acid (CH(2)-SH --> CH(2)-CH(3)). Both disulfide mutants are less stable and exist as molten globules in the monomeric state. Interestingly, both mutants dimerize, though with slightly lower affinities compared to the native protein. NMR studies suggest a molten globule-like structure also in the dimeric state. Structures, sequence analysis, and mutagenesis studies have shown that the conserved hydrophobic residues are packed against each other in the protein core and that H bonding and van der Waals interactions stabilize the dimer interface. Deleting either disulfide in IL-8 results in substantial loss in receptor activity, indicating that both disulfides are critical for function in the folded protein. These data together suggest that the packing interactions of the hydrophobic core determine IL-8 monomer fold, that disulfides play only a marginal role in dimer formation, and that the stability imparted by the disulfides is intimately coupled to fold and function. Study holds ProTherm entries: 23670, 23671, 23672, 23673, 23674, 23675 Extra Details: The variant of IL-8 (residues 1-66) was used in this study intramolecular disulfides; conserved hydrophobic residues; receptor activity; packing interactions

Submission Details

ID: fcTxhFjX3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:54 p.m.

Version: 1

Publication Details
Rajagopalan L;Chin CC;Rajarathnam K,Biophys. J. (2007) Role of intramolecular disulfides in stability and structure of a noncovalent homodimer. PMID:17513351
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
1IL8 1991-01-15 THREE-DIMENSIONAL STRUCTURE OF INTERLEUKIN 8 IN SOLUTION
1ROD 1996-06-10 CHIMERIC PROTEIN OF INTERLEUKIN 8 AND HUMAN MELANOMA GROWTH STIMULATING ACTIVITY PROTEIN, NMR
1IKL 1995-10-15 NMR study of monomeric human interleukin-8 (minimized average structure)
1ILP 1998-12-23 CXCR-1 N-TERMINAL PEPTIDE BOUND TO INTERLEUKIN-8
1IKM 1995-10-15 NMR study of monomeric human interleukin-8 (30 structures)
2IL8 1991-01-15 THREE-DIMENSIONAL STRUCTURE OF INTERLEUKIN 8 IN SOLUTION
5WDZ 2017-11-29 Structure of monomeric Interleukin-8 (1-66)
1ILQ 1998-12-23 CXCR-1 N-TERMINAL PEPTIDE BOUND TO INTERLEUKIN-8 (MINIMIZED MEAN)
4XDX 2015-12-23 0.95 The crystal structure of soluble human interleukin 8 expressed in Pichia pastoris
5D14 2015-12-23 1.0 The atomic resolution crystal structure of human IL-8
3IL8 1992-10-15 2.0 CRYSTAL STRUCTURE OF INTERLEUKIN 8: SYMBIOSIS OF NMR AND CRYSTALLOGRAPHY
1ICW 1997-03-12 2.01 INTERLEUKIN-8, MUTANT WITH GLU 38 REPLACED BY CYS AND CYS 50 REPLACED BY ALA
1QE6 2000-03-22 2.35 INTERLEUKIN-8 WITH AN ADDED DISULFIDE BETWEEN RESIDUES 5 AND 33 (L5C/H33C)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
94.9 Interleukin-8 P46653 IL8_CERAT
95.9 Interleukin-8 P67814 IL8_MACNE
95.9 Interleukin-8 P67813 IL8_MACMU
100.0 Interleukin-8 P10145 IL8_HUMAN