Nanomolar Protein-Protein Interaction monitoring with a label-free protein-probe technique

Valtonen, S., Vuorinen, E., Kariniemi, T., Eskonen, V., Le Quesne, J., Bushell, M., Härmä, H. and Kopra, K. (2020) Nanomolar Protein-Protein Interaction monitoring with a label-free protein-probe technique. Analytical chemistry, 92(24), pp. 15781-15788. (doi: 10.1021/acs.analchem.0c02823) (PMID:33237744) (PMCID:PMC7745204)

Abstract

Protein-protein interactions (PPIs) are an essential part of correct cellular functionality, making them increasingly interesting drug targets. While Förster resonance energy transfer-based methods have traditionally been widely used for PPI studies, label-free techniques have recently drawn significant attention. These methods are ideal for studying PPIs, most importantly as there is no need for labeling of either interaction partner, reducing potential interferences and overall costs. Already, several different label-free methods are available, such as differential scanning calorimetry and surface plasmon resonance, but these biophysical methods suffer from low to medium throughput, which reduces suitability for high-throughput screening (HTS) of PPI inhibitors. Differential scanning fluorimetry, utilizing external fluorescent probes, is an HTS compatible technique, but high protein concentration is needed for experiments. To improve the current concepts, we have developed a method based on time-resolved luminescence, enabling PPI monitoring even at low nanomolar protein concentrations. This method, called the protein probe technique, is based on a peptide conjugated with Eu chelate, and it has already been applied to monitor protein structural changes and small molecule interactions at elevated temperatures. Here, the applicability of the protein probe technique was demonstrated by monitoring single-protein pairing and multiprotein complexes at room and elevated temperatures. The concept functionality was proven by using both artificial and multiple natural protein pairs, such as KRAS and eIF4A together with their binding partners, and C-reactive protein in a complex with its antibody.

• Item Type: Articles
• Additional Information: This work was supported by the Academy of Finland (296225, 329012, 323433, and 296093), Medical Research Council Technology (LifeArc)–Development Gap Fund, Instrumentarium Science Foundation, Drug Research Doctoral Programme of the University of Turku, Finnish Concordia Fund, Finnish Academy of Science and Letters (foundation of Vilho, Yrjö, and Kalle Väisälä), and Cancer Research U.K. (A17196 and A29252).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Le Quesne, Professor John
• Authors: Valtonen, S., Vuorinen, E., Kariniemi, T., Eskonen, V., Le Quesne, J., Bushell, M., Härmä, H., and Kopra, K.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: Analytical chemistry
• Publisher: American Chemical Society
• ISSN: 1520-6882
• ISSN (Online): 1520-6882
• Published Online: 25 November 2020
• Copyright Holders: Copyright © 2020 American Chemical Society
• First Published: First published in Anal. Chem. 2020, 92, 24, 15781–15788
• Publisher Policy: Reproduced under a Creative Commons licence