Measuring the force of single protein molecule detachment from surfaces with AFM.

摘要: Atomic force microscopy (AFM) was used to measure the non-specific detachment of single fibrinogen molecules from glass surfaces. The identification unbinding events based on characteristics parabolic curves, recorded during stretching protein molecules. Fibrinogen were covalently bound Si(3)N(4) AFM tips, previously modified with 3-aminopropyl-dimethyl-ethoxysilane, through a homobifunctional poly(ethylene glycol) linker bearing two hydroxysulfosuccinimide esters. most probable found be 210 pN, when tip retracting velocity 1400 nm/s, while distribution distances indicated that chain can elongated beyond length physical conformation before detachment. dependence loading rate examined and dynamics binding surface amenable simple expression Bell-Evans theory. theory's expansion, however, by incorporating concept rupture parallel residue-surface bonds could only describe for small number such bonds. Finally, mathematical Worm-Like Chain model fit curves interpretations are suggested description multiple events.