ProteoChip-based library screening of integrin alpha5beta1 antagonists from Korean medicinal plant extracts

Integrins consist of transmembrane glycoproteins noncovalently associated to form alphabeta heterodimers. Various alpha/beta associations determine binding specieficities for cell surface molecules of the immunoglobulin superfamily as well as for extracellular matrix components. Through their cytoplasmic domains, integrins are responsible for the transmission of signals between the intracellular and the extracellular environment. We immobilized an integrin alpha5beta1 microarray on a ProteoChip to screen Korean medicinal plant extracts for binding activity. The microarray preserved the integrin alpha5beta1-fibronectin interaction, and was suppressed by the synthetic RGD peptide. We identified ten extracts with high integrin affinity using a high-throughput, competitive inhibition assay. We also demonstrate the biological function of these extracts in HUVECs.