Probing Interaction of Lipid-Modified Wnt Protein and Its Receptors by ELISA.

ABSTRACT

Wnts are lipid-modified proteins that regulate stem cell signaling via Frizzled receptors on the cell surface. Determination of binding interactions between lipid-modified Wnt proteins and their Frizzled receptors has been challenging due to the lack of availability of facile detection methods and technical hurdles associated with generating the relevant reagents. Here we report an enzyme-linked immunosorbent assay to measure the binding of a biotinylated form of lipid-modified Wnt3a to the extracellular cysteine-rich domain of Frizzled receptor. The method described herein is robust and rapid, uses minimum volumes of reagents, and can be conducted in a high-throughput format. Because of these attributes, the method could find utility in drug discovery applications such as characterizing the effect of pharmacological inhibitors on Wnt signaling without the need for sophisticated biophysical instrumentation.