Effect of a Hybrid Peptide Derived from Platelet Type I and Type III Collagen Receptors on CHO-65 Cells

The function of the platelet collagen receptor, 65-kDa, specific for type I collagen (CI), in eukaryotic cells remains elusive. In order to examine the effect of posttranslational modification of the receptor, we have made a construct, which contains the 65-kDa cDNA ligated into pcDNA3 (eukaryotic expression vector) by using standard cloning methodologies. The construct was transfected into CHO (CHO-65) cells, which expressed the protein, detectable by immunoblots [using the anti-65kDa antibodies (65-Ab)], and flow cytometry confirmed expression on the cell surface. A binding assay was used to evaluate the interaction of the expressed protein with CI. A chemically synthesized hybrid peptide (cHyB) containing the active peptides derived from the platelet receptors for types I and III collagen (9 amino acids each with a linker of 10 amino acid residues) inhibited the binding of the 65-Ab and FITC-CI on the CHO-65 cells. These results suggest that the 65-kDa proteins play a role in the interaction with CI and could potentially lead to new therapeutic development for an anti-platelet agent.