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Cell-cell adhesion mediated by specific cell-surface molecules is essential for multicellular development. Here we quantify de-adhesion forces at the resolution of individual cell-adhesion molecules, by controlling the interactions between single cells and combining single-molecule force spectroscopy with genetic manipulation. Our measurements are focused(More)
We used an atomic force microscope (AFM) to produce an image of a mixed layer of group A and O red blood cells with a contrast based only on the measured strength of a specific receptor-ligand pair. The image was obtained by measuring and plotting for each image pixel the adhesion force between the mixed RBC layer and the AFM tip functionalized with Helix(More)
At embryo implantation, it is postulated that the initial contact between blastocyst and maternal tissues is by adhesion of the trophoblast to the uterine epithelium. This cell-to-cell interaction is thought to be critical for implantation, although the actual adhesive forces have never been determined. In the present study, the atomic force microscope(More)
Protein-carbohydrate interactions are involved in diverse regulatory processes. To help understand the mechanics and kinetics of dissociation of receptor-ligand complexes, we have analyzed the separation of lactose and the N-glycan chains of asialofetuin (ASF) from three lectins and an immunoglobulin G fraction by surface plasmon resonance at zero force and(More)
Quantitative analysis of cellular interactions with the extracellular environment is necessary to gain an understanding of how cells regulate adhesion in the development and maintenance of multicellular organisms, and how changes in cell adhesion contribute to diseases. We provide a practical guide to quantify the adhesive strength of living animal cells to(More)
P-pili of uropathogenic Escherichia coli mediate the attachment to epithelial cells in the human urinary tract and kidney and therefore play an important role in infection. A better understanding of this mechanism could help to prevent bacteria from spreading but also provides interesting insights into molecular mechanics for future nanotech applications.(More)
dispersed genes in different lineages. First, the cluster may have been broken up in organisms with elevated rates of genome evolution, such as C. intestinalis, C. elegans and Drosophila melanogaster. This implies that cluster integrity in other lineages may not be due to selection. Conversely, clusters may have been maintained in some lineages due to(More)
In the past 25 years many techniques have been developed to characterize cell adhesion and to quantify adhesion forces. Atomic force microscopy (AFM) has been used to measure forces in the pico-newton range, an experimental technique known as force spectroscopy. We modified such an AFM to measure adhesion forces between live cells or between cells and(More)
The capacity of integrins to mediate adhesiveness is modulated by their cytoplasmic associations. In this study, we describe a novel mechanism by which alpha4-integrin adhesiveness is regulated by the cytoskeletal adaptor paxillin. A mutation of the alpha4 tail that disrupts paxillin binding, alpha4(Y991A), reduced talin association to the alpha4beta1(More)
Cell adhesion mechanically couples cells to surfaces. The durability of individual bonds between the adhesive receptors and their ligands in the presence of forces determines the cellular adhesion strength. For adhesive receptors such as integrins, it is a common paradigm that the cell regulates its adhesion strength by altering the affinity state of the(More)