Practical guide to characterize biomolecule adsorption on solid surfaces (Review)

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Microscale adhesion patterns for the precise localization of amoeba

In order to get a better understanding of amoeba-substrate interactions in the processes of cellular adhesion and directional movement, we engineered glass surfaces with defined local adhesion characteristics at a micrometric scale. Amoeba (Dictyostelium dicoideum) is capable to adhere to various surfaces independently of the presence of extracellular matrix proteins. This paper describes the strategy used to create selective adhesion motifs using an appropriate surface chemistry and shows the first results of locally confined amoeba adhesion. The approach is based on the natural ability of Dictyostelium to adhere to various types of surfaces (hydrophilic and hydrophobic) and on its inability to spread on inert surfaces, such as the block copolymer of polyethylene glycol and polypropylene oxide, named Pluronic. We screened diverse alkylsilanes, such as methoxy, chloro and fluoro silanes for their capacity to anchor Pluronic efficiently on a glass surface. Our results demonstrate that hexylmethyldichlorosilane (HMDCS) was the most appropriate silane for the deposition of Pluronic. A complex dependence between the physicochemistry of the silanes and the polyethylene glycol block copolymer deposition was observed. Using this method, we succeed in scaling down the micro-fabrication of pluronic-based adhesion motifs to the amoebaComment: Microelectronic Engineering (2008) in pres

Adsorption rate constants of therapeutic proteins and surfactants for material surfaces

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Insulin Aggregation at a Dynamic Solid–Liquid–Air Triple Interface

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Dual Effect of (LK)nL Peptides on the Onset of Insulin Amyloid Fiber Formation at Hydrophobic Surfaces

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Phenol-soluble modulins form amyloids in contact with multiple surface chemistries

International audienceFunctional amyloids are commonly produced by many microorganisms and their biological functions are numerous. Staphylococcus aureus can secrete a group of peptides named phenol-soluble modulins (PSMs) in their biofilm extracellular matrix. PSMs have been found inside biofilms both in their soluble form and assembled into amyloid structures. Yet, the actual biological function of these amyloids has been highly debated. Here, we assessed the ability of PSMs to form amyloids in contact with different abiotic surfaces to unravel a potential unknown bioadhesive and/or biofilm stabilization function. We combined surface plasmon resonance imaging, fluorescence aggregation kinetics, and FTIR spectroscopy in order to evaluate the PSM adsorption as well as amyloid formation properties in the presence of various surface chemistries. Overall, PSMs adsorb even on low-binding surfaces, making them highly adaptable adsorbants in the context of bioadhesion. Moreover, PSMs' aggregation potential to form amyloid aggregates is not impacted by the presence of the surface chemistries tested. This versatility regarding adsorption and amyloid formation may imply a possible role of PSMs in biofilm adhesion and/or structure integrity

Functional mapping of conserved, surface-exposed charges of antibody variable domains.

Surface-exposed charges can affect protein structure, stability and solubility as well as the kinetics of both the folding process and interaction with binding partners. We have investigated the influence on kinetic interaction parameters of 14 conserved, surface-exposed charges located away from the paratope in the variable domains of two antibodies of different specificity. We found that conserved, surface-exposed, charged framework residues are asymmetrically distributed on opposite faces of both VH and VL domains. Some of the charges play a critical role in protein folding and stability. While electrostatic forces within or close to the binding interface can be used to optimize the association rate, we confirmed the predicted minor effects of charge modifications remote from the binding site. They had no effect on the dissociation rate parameter. Our study demonstrates the role of residues remote from the interaction site in the recognition function as well as the limited effect of surface charge modifications in antibody fragments on kinetic interaction parameters

Anodic deposit from respiration metabolic pathway of Escherichia coli

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