Agilent 5991-3296EN Single Molecule Force Spectroscopy (SMFS) Using the 7500 AFM - Application Note c2014102 free download

File name 5991-3296EN Single Molecule Force Spectroscopy (SMFS) Using the 7500 AFM - Application Note c2014102

Keysight Technologies Single Molecule Force Spectroscopy (SMFS) Using the 7500AFM Application Note Introduction Avidin-Biotin Interaction Study Using SMFS The atomic force microscope (AFM) 1 is Single Molecule Force Spectroscopy can well known for its high imaging resolution be used to study the interaction of pro- even at ambient environment and room teins. For this, an upgraded sensor design temperature. Besides that, it can be used to is necessary. One binding partner has to be measure forces, accurately. Its force resolu- bound to the apex of the AFM tip using a tion at room temperature is high enough to lexible linker 9, 10, 11, while the other bind- measure forces as small as weak bindings ing partner is immobilized on the sample between biological molecules 2, 3, 4, 5, 6. Those surface. Interaction force measurements abilities make the AFM, especially force dis- are monitored by performing force distance tance based AFM methods a valuable tool to cycles. Hereby, the tip is approached until it investigate biological functions 7, 8. touches the surface. Eventually this results in a bond forming between the ligand (e.g. For biological processes weak interactions an organic molecule, peptide, toxin of full play a crucial role. Usually, ligand-receptor protein) bound to the tip and the receptor type complexes of proteins (e.g. antibodies, molecule (typically a protein) immobilized enzymes) and/or other organic biomolecules on the sample surface. Subsequent retrac- (e.g. vitamins, hormones) are formed. The tion results in loading of the bond with an lifetime and stability of such formed com- increasing force ramp. At a certain force the plexes is optimized for its biological func- bond ruptures and the bent cantilever jumps tion. Therefore measuring that weak interac- off the surface into its equilibrium posi- tion of proteins is impor