The interaction of biotin-binding proteins with biotinylated gramicidin (gA5XB) was studied by monitoring single-channel activity and sensitized photoinactivation kinetics. It was discovered that the addition of streptavidin or avidin to the bathing solutions of a bilayer lipid membrane (BLM) with incorporated gA5XB induced the opening of a channel characterized by approximately doubled single-...

Neurofilaments are found in abundance in the cytoskeleton of neurons, where they act as an intracellular framework protecting the neuron from external stresses. To elucidate the nature of the mechanical properties that provide this protection, we measure the linear and nonlinear viscoelastic properties of networks of neurofilaments. These networks are soft solids that exhibit dramatic strain st...

In the present review, we describe current knowledge about synthesis of borate crosslinked rhamnogalacturonan II (RG-II) and it physiological roles. RG-II is a portion of pectic polysaccharide with high complexity, present in primary cell wall. It is composed of homogalacturonan backbone and four distinct side chains (A-D). Borate forms ester bonds with the apiosyl residues of side chain A of t...

In this letter we report Brillouin scattering measurements on methyl-methacrylate (MMA) gels crosslinked with varying amounts of ethylene-dimethacrylate (EDMA). We find that the k dependence of the phase velocity changes on increasing the cross-link content. For higher concentrations of crosslink we observe maxima and minima in the k dependence of the phase velocity. We associate these minima a...

We explore the effect of random permanent cross-links on a system of directed polymers confined between two planes with their end points free to slide on them. We treat the cross-links as quenched disorder and we use a semimicroscopic replica field theory to study the structure and elasticity of this system. Upon increasing the cross-link density, we get a continuous gelation transition signale...

Hydrogels of 2-hydroxyethyl methacrylate (HEMA) cross-linked with N,N′-cystaminebis(acrylamide) (CBA) were prepared inside microchannels using an in situ photopolymerization for the study of chemical-responsive microgels. By chemically reducing disulfide bonds with dithiothreitol (DTT), the cross-link density of the hydrogel network decreased, leading to an observable swelling of the hydrogel. ...

Fanconi anemia is characterized by hypersensitivity to DNA interstrand crosslinks (ICLs) and susceptibility to tumor formation. Despite the identification of numerous Fanconi anemia (FANC) genes, the mechanism by which proteins encoded by these genes protect a cell from DNA interstrand crosslinks remains unclear. The recent discovery of two DNA helicases that, when defective, cause Fanconi anem...

Monomethoxy poly(ethylene glycol)-b-poly(Tyr(alkynyl)-OCA), a biodegradable amphiphilic block copolymer, was synthesized by means of ring-opening polymerization of 5-(4-(prop-2-yn-1-yloxy)benzyl)-1,3-dioxolane-2,4-dione (Tyr(alkynyl)-OCA) and used to prepare core cross-linked polyester micelles via click chemistry. Core cross-linking not only improved the structural stability of the micelles bu...

We study the dynamics of a pure-phase domain in a quenched melt of crosslinked polymers. Starting from de Gennes's mean-field theory, we obtain a pinning down of the