Effects of core mutations on the folding of a beta-sheet protein: implications for backbone organization in the I-state.


Abstract

A series of core mutations were introduced into beta-strand segments of an immunoglobulin fold (the isolated first domain of CD2, CD2.d1) to examine their influence on the rapidly formed intermediate state (I-state) which transiently accumulates in the folding reaction [Parker, M. J., and Clarke, A. R. (1997) Biochemistry 36, 5786-5794]. The residue changes were chemically conservative, each representing the removal of one or two methylene groups from aliphatic side chains. Predictably, the mutations destabilize the folded state with respect to the unfolded state by about 1.1 +/- 0.7 kcal mol-1 per methylene group removed. However, when the folding reaction is dissected by transient kinetic analysis into its component steps, six out of the nine mutations lead to a stabilization of the I-state. The direction and magnitude of these effects on the global stability of the transient intermediate are well correlated with changes in secondary structure propensity occasioned by the substitutions. The results show that, although side chain interactions are extremely weak in this early phase of folding, the beta-strand conformation of the polypeptide chain is established. In the next phase of the reaction, the rate-limiting transition state is attained by the formation of a tightly localized hydrophobic nucleus which includes residues V30, I18, and V78. Interestingly, in almost all immunoglobulin domains of extracellular proteins, the latter pair are cysteine residues which form a disulfide bridge. Study holds ProTherm entries: 5692, 5693, 5694, 5695, 5696, 5697, 5698, 5699, 5700, 5701, 5702, 5703, 5704 Extra Details: core mutation; beta-strand segment; intermediate state;,aliphatic side chain; global stability; hydrophobic nucleus

Submission Details

ID: fpkojRpy3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:30 p.m.

Version: 1

Publication Details
Lorch M;Mason JM;Clarke AR;Parker MJ,Biochemistry (1999) Effects of core mutations on the folding of a beta-sheet protein: implications for backbone organization in the I-state. PMID:9931001
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
1T6W 2005-02-15 RATIONAL DESIGN OF A CALCIUM-BINDING ADHESION PROTEIN NMR, 20 STRUCTURES
1CCZ 1999-04-05 1.8 CRYSTAL STRUCTURE OF THE CD2-BINDING DOMAIN OF CD58 (LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN 3) AT 1.8-A RESOLUTION
1CDC 1995-09-15 2.0 CD2, N-TERMINAL DOMAIN (1-99), TRUNCATED FORM
1A64 1998-05-27 2.0 ENGINEERING A MISFOLDED FORM OF RAT CD2
1A6P 1998-06-17 2.08 ENGINEERING OF A MISFOLDED FORM OF CD2
2DRU 2006-07-04 2.6 Crystal structure and binding properties of the CD2 and CD244 (2B4) binding protein, CD48
1HNG 1995-02-07 2.8 CRYSTAL STRUCTURE AT 2.8 ANGSTROMS RESOLUTION OF A SOLUBLE FORM OF THE CELL ADHESION MOLECULE CD2
1A7B 1998-06-17 3.1 ENGINEERING A MISFOLDED FORM OF CD2

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
99.7 T-cell surface antigen CD2 P08921 CD2_RAT