attana - sensor technologies

Avidity

To investigate detailed kinetics in an in situ environment provide crucial information about the interaction such as avidity effects occurring at the cell surface. This can easily be observed and characterized by using Attana’s unique “one-stop-shop" system where the the binding events can be determined from both a biochemical and cell-based assay.

Interactions those were previously just possible to study at the direct macromolecular level can now be analyzed label-free in the native biological context at the cell surface in order to fully understand the details of the underlying biological mechanism.

What is really the difference in analyzing an interaction between two binding partners in a biochemical assay and studying the same interaction occurring at the cell surface? Quite a few things can be different when analyzing an interaction occurring in its native complex cell surface environment. Added features utilizing cell-based kinetic assays are biologically relevant information such as surface target accessibility, avidity and drugability. Further, potentially detrimental off-target interactions can easily be identified during a first screening procedure allowing for only the correct candidates to proceed to the next step in the process and eliminate those candidates of poor quality. 

In an assay analyzing the interaction at the cell surface there is no possibility of manipulating the local microenvironment surrounding the target cell surface receptor. It is not uncommon for cancer cells that receptors can be found to be expressed in clusters at the surface membrane generating areas with a high surface density of the receptor. If a target molecule has the possibility to simultaneously bind several receptors a phenomenon referred to as avidity may arise. Avidity will greatly strengthen the interaction. The classical 1:1 binding model will not be applicable in avidity situations. Attana provides a sophisticated software option called TraceDrawer where several advanced binding models are included.