scispace - formally typeset
Search or ask a question
Author

Michel Grandbois

Bio: Michel Grandbois is an academic researcher from Université de Sherbrooke. The author has contributed to research in topics: Surface plasmon resonance & Cytoskeleton. The author has an hindex of 29, co-authored 75 publications receiving 3574 citations. Previous affiliations of Michel Grandbois include University of Missouri & Université de Montréal.


Papers
More filters
Journal ArticleDOI
12 Mar 1999-Science
TL;DR: The rupture force of single covalent bonds under an external load was measured with an atomic force microscope (AFM) and calculations that were based on density functional theory corroborate the measured values.
Abstract: The rupture force of single covalent bonds under an external load was measured with an atomic force microscope (AFM). Single polysaccharide molecules were covalently anchored between a surface and an AFM tip and then stretched until they became detached. By using different surface chemistries for the attachment, it was found that the silicon-carbon bond ruptured at 2.0 ± 0.3 nanonewtons, whereas the sulfur-gold anchor ruptured at 1.4 ± 0.3 nanonewtons at force-loading rates of 10 nanonewtons per second. Bond rupture probability calculations that were based on density functional theory corroborate the measured values.

1,018 citations

Journal ArticleDOI
TL;DR: The results demonstrate the ability of the plasma membrane to locally produce multiple interdependent tethers-a process that could play an important role in the mechanical association of cells with their environment.

209 citations

Journal ArticleDOI
TL;DR: Results show that the adhesion, mediated by only a few receptor-ligand pairs, produces sufficient contrast for the affinity image formation.
Abstract: SUMMARY 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 pomatia lectin. The high specificity of that lectin for the N-acetylgalactosamine-terminated glycolipids present in the membrane of group A RBCs enabled us to discriminate between the two cell populations and to produce an image based on affinity contrast. The rupture force of the adhesion events leading to the image formation were quantitatively analyzed and compared to rupture forces measured with the same AFM tip on N-acetylgalactosamine tethered to agarose beads. The mean rupture force was found to be 65 pN when measured on the group A RBCs and 35 pN on the agarose beads. These results show that the adhesion, mediated by only a few receptor–ligand pairs, produces sufficient contrast for the affinity image formation. (J Histochem Cytochem 48:719–724, 2000)

207 citations

Journal ArticleDOI
TL;DR: These experiments suggest that it is possible to observe single enzymes at work in small channels, which are created by the hydrolysis of membrane phospholipids, and supports the single-enzyme hypothesis.

190 citations

Journal ArticleDOI
TL;DR: There is compelling evidence for a novel intracrine mode of genomic regulation by GPCRs that implies either the endocytosis and nuclear translocation of peripheral-liganded G PCR and (or) the activation of nuclearly located GPCR by endogenously produced, nonsecreted ligands.
Abstract: G-protein-coupled receptors (GPCRs) comprise a wide family of monomeric heptahelical glycoproteins that recognize a broad array of extracellular mediators including cationic amines, lipids, peptide...

163 citations


Cited by
More filters
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: The atomic force microscope (AFM) is not only used to image the topography of solid surfaces at high resolution but also to measure force-versus-distance curves as discussed by the authors, which provide valuable information on local material properties such as elasticity, hardness, Hamaker constant, adhesion and surface charge densities.

3,281 citations

Journal ArticleDOI
TL;DR: Recent discoveries have uncovered how plant cells synthesize wall polysaccharides, assemble them into a strong fibrous network and regulate wall expansion during cell growth.
Abstract: Plant cells encase themselves within a complex polysaccharide wall, which constitutes the raw material that is used to manufacture textiles, paper, lumber, films, thickeners and other products. The plant cell wall is also the primary source of cellulose, the most abundant and useful biopolymer on the Earth. The cell wall not only strengthens the plant body, but also has key roles in plant growth, cell differentiation, intercellular communication, water movement and defence. Recent discoveries have uncovered how plant cells synthesize wall polysaccharides, assemble them into a strong fibrous network and regulate wall expansion during cell growth.

2,832 citations

Journal ArticleDOI
TL;DR: This review is focused on current approaches emerging at the intersection of materials research, nanosciences, and molecular biotechnology, which is closely associated with both the physical and chemical properties of organic and inorganic nanoparticles.
Abstract: Based on fundamental chemistry, biotechnology and materials science have developed over the past three decades into today's powerful disciplines which allow the engineering of advanced technical devices and the industrial production of active substances for pharmaceutical and biomedical applications. This review is focused on current approaches emerging at the intersection of materials research, nanosciences, and molecular biotechnology. This novel and highly interdisciplinary field of chemistry is closely associated with both the physical and chemical properties of organic and inorganic nanoparticles, as well as to the various aspects of molecular cloning, recombinant DNA and protein technology, and immunology. Evolutionary optimized biomolecules such as nucleic acids, proteins, and supramolecular complexes of these components, are utilized in the production of nanostructured and mesoscopic architectures from organic and inorganic materials. The highly developed instruments and techniques of today's materials research are used for basic and applied studies of fundamental biological processes.

2,268 citations

Journal ArticleDOI
TL;DR: These techniques are described and illustrated with examples highlighting current capabilities and limitations of single-molecule force spectroscopy.
Abstract: Single-molecule force spectroscopy has emerged as a powerful tool to investigate the forces and motions associated with biological molecules and enzymatic activity. The most common force spectroscopy techniques are optical tweezers, magnetic tweezers and atomic force microscopy. Here we describe these techniques and illustrate them with examples highlighting current capabilities and limitations.

2,155 citations