αIIbβ3 CHO K1 cell line. (A) CHO K1 cells do not express αIIbβ3 (top). Transfected αIIbβ3 CHO K1 cells express αIIbβ3 at the cell surface, as detected by anti-β3 and PAC-1 antibody (bottom). (B) cRGDFG, a cyclic peptide that specifically binds to α5 and αV integrins, inhibits CHO K1 cell adhesion to 0.5% GRGDSC SAMs. (C) CHO K1 cells adhere to 0.5% GRGDSC SAMs in the absence of inhibitors, but (D) fail to adhere to the same substrate in the presence of [cRGDFG]=300 µM. (E) αIIbβ3 CHO K1 cells adhere to 0.5% GRGDSC SAMs in the presence of [cRGDFG]=300 µM, (F) this interaction is nulled by the presence of PAC-1.