Atomic Force Microscopy Study On The Modulation Of Polypeptide Aptamer APT On The Mechanical Properties Of Fibronectin Extradomain EDB

Fibronectin(Fn)is an important biological macromolecule that withstands and transmits mechanical forces within and between cells,and is a mechanically sensitive protein.Among them,the fibronectin extradomain EDB is only significantly expressed during embryogenesis and cardiovascular generation and in tumor cells,thereby triggering many important physiological processes,including cell adhesion,wound healing,signal transmission,proliferation and differentiation.The mechanical properties of EDB have an important impacton its physiological function.In this study,the mechanical properties of EDB were studied using single-molecule force spectroscopy based on atomic force microscopy,and the specific binding of peptide aptamer APT to EDB was used to change the extra fibronectin.The conformation of the domain EDB,thereby regulating the mechanical properties of the extra domain EDB of fibronectin.In our research,We constructed the Streptavidin-biotin polymer biomolecule system and the SdrG-Fgb monomer biomolecule system,and conducted single-molecule force spectroscopy experiments based on atomic force microscopy.We found that the peptide aptamer APT can significantly affect the mechanical properties of the extra domain EDB of fibronectin.In the absence of APT,the unfolding force of EDB is between 65-95pN,in the presence of APT,the unfolding force of the EDB force is reduced,so that the unfolding force of EDB(less than 10 pN)cannot be clearly detected by the atomic force microscope.Through the above research results,we adapted for peptide body APT domain structure of fibronectin extra EDB's regulation are science described,the mechanical properties of reinforced ligand APT understanding of EDB receptor specificity interaction,at the same time can provide to EDB for target tumor detection and treatment to provide theoretical and experimental basis for establishing the connection between the protein function and micromechanics,conformation and is of great significance.