Microscale thermophoresis quantifies biomolecular interactions under previously challenging conditions

Area of Science:

• Biochemistry
• Molecular Biology
• Biophysics

Background:

• Microscale thermophoresis (MST) is a technique for analyzing molecular interactions in solution.
• It relies on the directed movement of molecules within a temperature gradient.
• MST is sensitive to binding-induced changes in molecular properties like size, charge, and conformation.

Purpose of the Study:

• To highlight the quantitative analysis of biomolecular interactions using MST.
• To demonstrate the adaptability and broad applicability of MST assays.
• To showcase MST's capability in analyzing challenging binding events in complex biological settings.

Main Methods:

• Utilizes an infrared laser for local heating and fluorescence detection to analyze molecule mobility in temperature gradients.
• Standard MST involves one fluorescently labeled binding partner; label-free MST exploits intrinsic UV-fluorescence.
• Assays are adaptable to various buffer conditions, additives, and even complex bioliquids like cell lysate.

Main Results:

• MST enables quantitative analysis of protein interactions with low sample consumption.
• The technique is sensitive to various binding-induced molecular property changes.
• MST can analyze interactions with high molecular weight ratios, including small molecules and peptides with proteins.
• Label-free MST is feasible by utilizing intrinsic protein UV-fluorescence.
• Assays can be performed in complex media like cell lysate, approximating in vivo conditions.
• Quantifiable binding modes include dimerization, cooperativity, and competition.

Conclusions:

• MST is a versatile technique for quantitative analysis of biomolecular interactions.
• Its flexibility allows for assay design in diverse and complex experimental settings.
• MST is suitable for studying challenging binding events across various life science fields.