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Updated: Sep 5, 2026
A Comparative Approach to Characterize the Landscape of Host-Pathogen Protein-Protein Interactions
Published on: July 18, 2013
Elucidating the Stoichiometries of Host-Pathogen Protein Interactions with Mass Photometry
Emma-Jayne Proctor1,2, Sandeep Satapathy3,4, Martina Sanderson-Smith5,6
1Illawarra Health and Medical Research Institute (IHMRI), University of Wollongong, Wollongong, Australia.
Abstract:
Mass photometry (MP) is a single molecule technique that enables the characterization of individual proteins. Here we show a detailed workflow using the Refeyn OneMP to investigate molecular complexes, using the M53 protein, a plasminogen-binding group A streptococcal M-like protein (PAM), and human plasminogen as exemplar proteins. The methodology described herein confirmed a 1:1 binding stoichiometry for the M53-plasminogen complex. Additionally, MP was used to identify the oligomerization state, homogeneity, purity, and approximate molecular weights of each protein.
Insights
Mass photometry (MP) precisely characterizes individual proteins and their complexes. This study details an MP workflow to analyze protein molecular weight, oligomerization, and binding stoichiometry, exemplified by the M53-plasminogen interaction.
Area of Science:
- Biochemistry
- Biophysics
- Molecular Biology
Background:
- Mass photometry (MP) is an advanced single-molecule detection technique.
- Characterizing protein complexes is crucial for understanding biological functions.
Purpose of the Study:
- To present a detailed workflow for investigating protein complexes using mass photometry.
- To demonstrate the application of MP in determining binding stoichiometry, oligomerization state, homogeneity, purity, and molecular weights of proteins.
Main Methods:
- Utilized the Refeyn OneMP instrument for mass photometry measurements.
- Employed M53 protein, a plasminogen-binding group A streptococcal M-like protein (PAM), and human plasminogen as model systems.
Main Results:
- Confirmed a 1:1 binding stoichiometry between the M53 protein and human plasminogen.
- Successfully determined the oligomerization state, homogeneity, purity, and molecular weights of the investigated proteins.
Conclusions:
- Mass photometry provides a robust method for comprehensive characterization of individual proteins and their interactions.
- The presented workflow enables detailed analysis of molecular complexes, aiding in biochemical and biophysical research.
