Solid Phase Assays for Studying ECM Protein–Protein Interactions

Solid-phase assays provide a simple, rapid and robust method for the analysis of protein-protein interactions; i.e., does protein A interacts with protein B? In this assay, protein A (here termed as 'receptor') is adsorbed to the wells of an enzyme-linked immunosorbent assay (ELISA) plate (solid phase). The plate is then blocked using bovine serum albumin (BSA), and biotin-labelled protein B (here termed as 'ligand') is added. After washing the wells to remove unbound ligand, bound ligand is detected by addition of an avidin-peroxidase conjugate followed by a colorimetric detection step. This type of assay is particularly well suited for studying the interaction of ECM proteins with integrins. The screening of antagonists of integrin-ligand interactions in the pharmaceutical industry is an important area in which this assay is finding use.