Quantitation of protein-protein interactions by thermal stability shift analysis.


Abstract

Thermal stability shift analysis is a powerful method for examining binding interactions in proteins. We demonstrate that under certain circumstances, protein-protein interactions can be quantitated by monitoring shifts in thermal stability using thermodynamic models and data analysis methods presented in this work. This method relies on the determination of protein stabilities from thermal unfolding experiments using fluorescent dyes such as SYPRO Orange that report on protein denaturation. Data collection is rapid and straightforward using readily available real-time polymerase chain reaction instrumentation. We present an approach for the analysis of the unfolding transitions corresponding to each partner to extract the affinity of the interaction between the proteins. This method does not require the construction of a titration series that brackets the dissociation constant. In thermal shift experiments, protein stability data are obtained at different temperatures according to the affinity- and concentration-dependent shifts in unfolding transition midpoints. Treatment of the temperature dependence of affinity is, therefore, intrinsic to this method and is developed in this study. We used the interaction between maltose-binding protein (MBP) and a thermostable synthetic ankyrin repeat protein (Off7) as an experimental test case because their unfolding transitions overlap minimally. We found that MBP is significantly stabilized by Off7. High experimental throughput is enabled by sample parallelization, and the ability to extract quantitative binding information at a single partner concentration. In a single experiment, we were able to quantify the affinities of a series of alanine mutants, covering a wide range of affinities (∼ 100 nM to ∼ 100 μM).

Submission Details

ID: 35E8QAAe

Submitter: Shu-Ching Ou

Submission Date: Nov. 14, 2018, 11:23 a.m.

Version: 1

Publication Details
Layton CJ;Hellinga HW,Protein Sci (2011) Quantitation of protein-protein interactions by thermal stability shift analysis. PMID:21674662
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
3JYR 2009-09-22T00:00:00+0000 1.75 Crystal structures of the GacH receptor of Streptomyces glaucescens GLA.O in the unliganded form and in complex with acarbose and an acarbose homolog. Comparison with acarbose-loaded maltose binding protein of Salmonella typhimurium.
6L0Z 2019-09-27T00:00:00+0000 1.6 The crystal structure of Salmonella enterica sugar-binding protein MalE
6L3E 2019-10-10T00:00:00+0000 1.6 Crystal structure of Salmonella enterica sugar-binding protein MalE
3IO4 2009-08-13T00:00:00+0000 3.63 Huntingtin amino-terminal region with 17 Gln residues - Crystal C90
3OSQ 2010-09-09T00:00:00+0000 1.9 Maltose-bound maltose sensor engineered by insertion of circularly permuted green fluorescent protein into E. coli maltose binding protein at position 175
3OSR 2010-09-09T00:00:00+0000 2.0 Maltose-bound maltose sensor engineered by insertion of circularly permuted green fluorescent protein into E. coli maltose binding protein at position 311
3VD8 2012-01-04T00:00:00+0000 2.07 Crystal structure of human AIM2 PYD domain with MBP fusion
4FEB 2012-05-29T00:00:00+0000 2.8 Crystal Structure of Htt36Q3H-EX1-X1-C2(Beta)
4MY2 2013-09-27T00:00:00+0000 2.4 Crystal Structure of Norrin in fusion with Maltose Binding Protein
4WGI 2014-09-18T00:00:00+0000 1.85 A Single Diastereomer of a Macrolactam Core Binds Specifically to Myeloid Cell Leukemia 1 (MCL1)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
93.4 Maltose/maltodextrin-binding periplasmic protein P18815 MALE_KLEAE
94.0 Maltose/maltodextrin-binding periplasmic protein P19576 MALE_SALTY
99.7 Maltose/maltodextrin-binding periplasmic protein P0AEX9 MALE_ECOLI
99.7 Maltose/maltodextrin-binding periplasmic protein P0AEY0 MALE_ECO57