Isothermal Titration Calorimetry (ITC)

Based on the advanced isothermal titration calorimetry (ITC) platform established for drug discovery, Creative Biolabs can offer high-quality ITC services to support fragment-based screening, lead optimization, and protein-natural product interactions.

ITC is a physical method used to measure the heat exchange connected with molecular interactions at permanent temperature, mostly as an approach to detecting thermodynamic parameters connected with complex formation. Recently, ITC is applied to measuring the binding affinity of ligands for proteins and representatively used as a hit screening technique in high throughput screening. Experimental conditions enable to be customized to the special binding system being researched, for example, buffer and temperature. Furthermore, more information is able to be gained from working additional experiments under different buffer or temperature states.

Figure 1. ITC data plotted onto an enthalpy–entropy diagram (a), and Cooperative effects in protein–ligand binding (b). (Klebe 2015)

Fragment-Based Screening

Fragment-based screening has become an approach for the quick discovery and following elaboration of hits into quality lead compounds. This method is on account of the theory of screening simple low-molecular-mass compounds which produce a few high-quality interactions with the target site. ITC is a sensitive method to measure the weak binding of hits, and usually used for proteins proving limited stability in other orthogonal assays. In addition, ITC is a great predictor of successful determination of protein-ligand co-crystal structures.

Hit to Lead

Hit to lead strategies require control over the forces that maximize affinity towards the minded target and minimize affinity towards other proteins. A particular understanding of the interactions between a small-molecule ligand with its target protein is required for Hit to lead. Currently, ITC has become an available tool for hit optimization, and it has been used in several aspects, for example, determine the binding affinity, selectivity optimization, and thermodynamics guided optimization. By using the ITC which controls over the binding determinants of compounds provides a significant leverage in hit to lead.

Natural Compound Target Identification

ITC has been utilized to research the various types of interactions of the natural compound and potential drug targets. Mostly, drug targets are major components of the cell membrane or combine with compound to inhibit the binding and synthesis of ergosterol or membrane-surface enzymes and lipid biosynthesis. A great variety of molecular interactions can be determined using ITC for natural compounds target identification, such as protein-polyphenol, protein-alkaloid, protein-terpene, cyclodextrin-natural product, and nucleotide-natural product. A remarkable advantage of this approach is that it only needs a small quantity of sample and without the demand of any chemical modification.

Creative Biolabs provides other various drug discovery services. For more detailed information, please feel free to contact us or directly sent us an inquiry.

Reference

1. Klebe G (2015). “Applying thermodynamic profiling in lead finding and optimization”. Nature Reviews Drug Discovery 14(2), 95-110.
2. Callies O (2016). “Application of isothermal titration calorimetry as a tool to study natural product interactions”. Natural product reports 33(7):881-904.
3. Drinkwater N (2010). “Fragment-based screening by X-ray crystallography, MS and isothermal titration calorimetry to identify PNMT (phenylethanolamine N-methyltransferase) inhibitors”. Biochemical Journal 431(1), 51-61.

For Research Use Only.