AVS 46th International Symposium
    Biomaterial Interfaces Group Wednesday Sessions
       Session BI-WeA

Invited Paper BI-WeA7
Single Molecule Force Spectroscopy by AFM, Nanomechanics Meets Molecular Biology

Wednesday, October 27, 1999, 4:00 pm, Room 613/614

Session: Biology at the Nanoscale
Presenter: H.E. Gaub, Ludwig-Maximilians-Universität München, Germany
Authors: K. Tolksdorf, Ludwig-Maximilians-Universität München, Germany
M. Grandbois, Ludwig-Maximilians-Universität München, Germany
M. Rief, Ludwig-Maximilians-Universität München, Germany
H. Clausen-Schaumann, Ludwig-Maximilians-Universität München, Germany
H.E. Gaub, Ludwig-Maximilians-Universität München, Germany
Correspondent: Click to Email
Recent developments in AFM-instrumentation allow the manipulation of single molecules and measurements of intermolecular as well as intramolecular forces. We took advantage of the high spatial resolution of the AFM and developed mechanical experiments with single macromolecules. An overview on this novel kind of spectroscopy will be given and applications in the field of polymer and life sciences will be highlighted: receptor ligand interactions were measured in single molecular pairs. Lateral distributions of interaction partners on samples were mapped in a chemical imaging mode. The length distribution of individual grafted polymers at surfaces was imaged. Individual polymers and proteins that were anchored on a gold surface were picked up with the AFM tip and stretched, their viscolelasticity and yield strength was measured. Proteins were reversibly unfolded and the conformation forces were determined at the level of single secondary structure elements. DNA double strands were stretched and unzipped. A model was developed based on elastically coupled two-level systems that allows the description of basic features of the experimental results. @FootnoteText@ Rief, M.; Oesterhelt, F.; Heymann, B.; Gaub, H. E.Science 1997, 275, 1295-1298. Rief, M.; Gautel, M.; Oesterhelt, F.; Fernandez, J. M.; Gaub, H. E. Science 1997, 276, 1109-1112. M. Rief, H. Clausen-Schaumann , H.E. Gaub, Nature Struct. Biol. (1999), in press M. Grandbois, M. Beyer, M. Rief, H. Clausen-Schaumann ,H.E. Gaub, (1999),Science in press