Methods for analyzing and quantifying protein–protein interaction

Abstract

Genome sequencing has led to the identification of many proteins, which had not been recognized before. In consequence, the basic set of human proteins is generally known. Far less information, however, exists about protein–protein interactions, which are required and responsible for cellular activities and their control. Many protein isoforms that result from mutations, splice-variations and post-translational modifications also come into play. Until recently, interactions of only few protein partners could be analyzed in a single experiment. However, this does not meet the challenge of investigating the highly complex interaction patterns in cellular systems. It is made even more demanding by the need to determine the intensity of interactions quantitatively in order to properly understand protein interplay. Currently available techniques vary with respect to accuracy, reliability, reproducibility and throughput and their performances range from a mere qualitative demonstration of binding to a quantitative characterization of affinities. In this article, an overview is given of the methodologies available for analysis of protein–protein interactions.

Keywords::

• assay formats
• detection
• interactions
• proteomics
• quantification

Acknowledgements

The authors thank P Kunz for his valuable comments.

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• Protein–protein interactions (PPIs) are at the heart of almost all biological processes and present prime targets for therapeutic intervention.

• To study PPIs, there is a variety of techniques available offering either high-throughput analysis or absolute quantification.

• To fully appreciate the complexity of cellular proteomic interactions, new technologies are needed that integrate both these aspects.

• Once accomplished, these technologies will boost our understanding of PPIs, yielding new therapeutic targets and approaches.

Notes