Small Molecules Binding Protein Target

Label-Free Protein - Small Molecule Binding Assay

Label-free protein-small molecule assay provide direct binding measurement to determine if a small molecule binds to a given protein target.  The results are not generated based on functional activity.  Rather the small-molecule binding event is measured directly.

Traditional protein-small molecule interaction assays rely heavily on several components.  Most assays available today measure interaction indirectly.  For example, the disruption of a functional activity, or the presence or absence of a downstream by-product.  Other assays also require the use if radiometric reagents resulting in added safety and disposal precautions.  Additionally, to monitor disruption of a functional activity, the natural ligand must be identified, and one or both binding partners must be labeled thereby disrupting the native state.  Functional measurements also restrict such work to active protein forms.

Not all compounds that bind result in functional disruption.  Therefore certain binding compounds may be missed using functional detection systems.  As a result, protein-small molecule binding assays are particularly valuable in an orthogonal testing environment where hit confirmation data is required.  Direct-bind information is also needed when the functional activity of particular target cannot be measured since the target is in the inactive form.

The animation on the left demonstrates the activity detected in a direct bind, protein-small molecule assay.  A baseline read is estabilished, followed by a second read after small-molecule addition.  The data is provided as an end-point read.