Simultaneous atomic force microscope and fluorescence measurements of protein unfolding using a calibrated evanescent wave
AUTOR(ES)
Sarkar, Atom
FONTE
National Academy of Sciences
RESUMO
Fluorescence techniques for monitoring single-molecule dynamics in the vertical dimension currently do not exist. Here we use an atomic force microscope to calibrate the distance-dependent intensity decay of an evanescent wave. The measured evanescent wave transfer function was then used to convert the vertical motions of a fluorescent particle into displacement (SD = <1 nm). We demonstrate the use of the calibrated evanescent wave to resolve the 20.1 ± 0.5-nm step increases in the length of the small protein ubiquitin during forced unfolding. The experiments that we report here make an important contribution to fluorescence microscopy by demonstrating the unambiguous optical tracking of a single molecule with a resolution comparable to that of an atomic force microscope.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=516489Documentos Relacionados
- Atomic force microscope measurements and manipulation of Langmuir-Blodgett films with modified tips.
- Force and Compliance Measurements on Living Cells Using Atomic Force Microscopy (AFM)
- Athermalization in atomic force microscope based force spectroscopy using matched microstructure coupling
- Atomic force microscope measurements of long-range forces near lipid-coated surfaces in electrolytes.
- Stepwise unfolding of titin under force-clamp atomic force microscopy
