Mechanical perturbation-induced fluorescence change of green fluorescent protein

The force curve measurement mode of the atomic force microscope (AFM) is a powerful experimental technique in biotechnology. However, it is more effective if the spectroscopic properties of the biomolecule in the contact area can be simultaneously measured. Thus, we developed a confocal laser scanning microscope/AFM system. In this study, we simultaneously measured the fluorescence spectra of green fluorescent protein with the application of an external force in order to investigate the stability and dynamics of the beta-barrel structure. Consequently, the fluorescence was quenched by applying both compression and extension forces and the quenching efficiencies differed in each case. (C) 2005 American Institute of Physics.