Title
Engineering integrin-specific surfaces with a triple-helical collagen-mimetic peptide
Author
Catherine D. Reyes, Andrés J. García
Year
2003
Journal
Journal of Biomedical Materials Research Part A
Abstract
Integrin-mediated cell adhesion to extracellular matrix proteins anchors cells and triggers signals that direct cell function. The integrin α2β1 recognizes the glycine-phenylalanine-hydroxyproline-glycine-glutamate-arginine (GFOGER) motif in residues 502–507 of the α1(I) chain of type I collagen. Integrin recognition is entirely dependent on the triple-helical conformation of the ligand similar to that of native collagen. This study focuses on engineering α2β1-specific bioadhesive surfaces by immobilizing a triple-helical collagen-mimetic peptide incorporating the GFOGER binding sequence onto model nonadhesive substrates. Circular dichroism spectroscopy verified that this peptide adopts a stable triple-helical conformation in solution. Passively adsorbed GFOGER-peptide exhibited dose-dependent HT1080 cell adhesion and spreading comparable to that observed on type I collagen. Subsequent antibody blocking conditions verified the involvement of integrin α2β1 in these adhesion events. Focal adhesion formation was observed by immunofluorescent staining for α2β1 and vinculin on MC3T3-E1 cells. Model functionalized surfaces then were engineered using three complementary peptide-tethering schemes. These peptide-functionalized substrates supported α2β1-mediated cell adhesion and focal adhesion assembly. Our results suggest that this peptide is active in an immobilized conformation and may be applied as a surface modification agent to promote α2β1–specific cell adhesion. Engineering surfaces that specifically target certain integrin–ligand interactions and signaling cascades provides a biomolecular strategy for optimizing cellular responses in biomaterials and tissue engineering applications.
Instrument
J-810
Keywords
Circular dichroism, Secondary structure, Thermodynamics, Thermal stability, Biochemistry