This thesis consists of eight chapters. In Chapters 2 and 3, theapplication of AFM to biological systems is explored, both in air and inliquid. Chapter 2 deals with atomic force microscopy in air... Show moreThis thesis consists of eight chapters. In Chapters 2 and 3, theapplication of AFM to biological systems is explored, both in air and inliquid. Chapter 2 deals with atomic force microscopy in air and, as anexample, contains a study of filaments found in dividing yeast cells.Chapter 3 describes atomic force microscopy in liquid, both in contactmode and in tapping mode.In Chapters 4, 5, and 6 we discuss all steps that have to betaken in order to make the high-resolution MRFM experimentdescribed in Chapter 7 possible. As a first step, Chapter 4 provides amethod for immobilizing well-separated single molecules for AFMstudies in liquid. Next, in Chapter 5, the use of carbon nanotubes asAFM tips for molecular recognition force microscopy is discussed, anda description is given of the fabrication process of single-walled andmulti-walled carbon nanotube AFM tips. In Chapter 6, the last step isdiscussed: chemical characterization and functionalization of carbonnanotubes. In Chapter 7, all steps come together, and first results ofmolecular recognition force microscopy experiments on pea lectin andon mannan binding lectin are shown and discussed.To conclude, Chapter 8 provides a summarizing discussion andan outlook. Show less
The FIN1 gene from the yeast Saccharomyces cerevisiae encodes a basic protein with putative coiled-coil regions. Here we show that in large-budded cells a green fluorescent protein-Fin1 fusion... Show moreThe FIN1 gene from the yeast Saccharomyces cerevisiae encodes a basic protein with putative coiled-coil regions. Here we show that in large-budded cells a green fluorescent protein-Fin1 fusion protein is visible as a filament between the two spindle pole bodies. In resting cells the protein is undetectable, and in small-budded cells it is localized in the nucleus. During late mitosis it localizes on the spindle pole bodies. Filaments of cyano fluorescent protein-tagged Fin1 colocalize with filaments of green fluorescent protein-tagged Tub1 only in large-budded cells. By electron and atomic force microscopy we showed that purified recombinant Fin1p self-assembles into filaments with a diameter of ≈10 nm. Our results indicate that the Fin1 protein forms a cell cycle-specific filament, additional to the microtubules, between the spindle pole bodies of dividing yeast cells. Show less
