Fragment-Based Screening for Enzyme Inhibitors Using Calorimetry

Area of Science:

• Biophysical Chemistry
• Enzyme Kinetics
• Drug Discovery

Background:

• Isothermal titration calorimetry (ITC) is a sensitive method for studying binding thermodynamics and label-free enzyme kinetics.
• Conventional microcalorimetry is valuable for hit validation but limited in primary screening due to high reagent requirements and long assay times.

Purpose of the Study:

• To describe the application of nanocalorimetry and conventional microcalorimetry for screening compound libraries.
• To highlight nanocalorimetry's potential to overcome limitations of conventional ITC in fragment-based lead discovery.

Main Methods:

• Utilized isothermal titration calorimetry (ITC) with both conventional microcalorimeters and advanced nanocalorimeters.
• Applied label-free measurement techniques for enzymatic reactions.
• Screened compound libraries, including those typical in fragment-based lead discovery.

Main Results:

• Demonstrated the utility of nanocalorimetry for screening large compound libraries (500-1000 compounds).
• Showcased nanocalorimetry's ability to overcome the limitations of conventional ITC regarding reagent consumption and measurement duration.
• Validated the use of microcalorimetry for hit validation and characterization.

Conclusions:

• Nanocalorimetry offers a viable solution for primary screening of compound libraries in drug discovery.
• Both nanocalorimetry and conventional microcalorimetry are powerful tools for enzyme inhibitor screening.
• Label-free calorimetric methods provide essential thermodynamic and kinetic data for characterizing molecular interactions.