High-precision isothermal titration calorimetry with automated peak-shape analysis

Area of Science:

• Biophysical Chemistry
• Biochemistry
• Thermodynamics

Background:

• Isothermal titration calorimetry (ITC) is a key technique for studying molecular interaction thermodynamics.
• ITC data analysis is often limited by instrumental baseline noise and adventitious events.
• Accurate thermodynamic parameter determination relies on precise isotherm construction.

Purpose of the Study:

• To develop an automated method for peak assignment in ITC experiments.
• To improve the precision and reliability of thermodynamic data derived from ITC.
• To enhance the detection limits for weak binding interactions and low enthalpy changes.

Main Methods:

• Automated peak assignment using singular value decomposition (SVD) for peak-shape analysis.
• Least-squares modeling of local pre- and post-injection baselines.
• Filtering of short-term noise and adventitious events from power traces.

Main Results:

• Effective filtering of instrumental noise and adventitious events.
• Accurate statistical error estimates for individual isotherm data points.
• Improved detection limits for high-affinity or low-enthalpy binding reactions.

Conclusions:

• The developed method significantly enhances the precision of derived thermodynamic parameters.
• This approach offers more reliable ITC data analysis, particularly for challenging binding reactions.
• Automated peak assignment provides robust and statistically validated thermodynamic insights into molecular interactions.