Search results for "Biotinylation"
showing 10 items of 76 documents
Molecular recognition in biotin-streptavidin systems and analogues at the air-water interface
1992
Abstract Specific interaction between biotin and the protein streptavidin in monolayers of synthetic lipids with biotin headgroups has been shown to lead to formation of highly ordered two-dimensional streptavidin crystals. The same behaviour is observed when using desthiobiotin as lipid headgroup which exhibits a significantly lower binding constant compared with biotin (5 × 10 13 M -1 compared with 10 15 M -1 ). This offers the possibility of detaching competetively the 2D crystalline streptavidin layer by addition of free biotin to the aqueous phase. Use of lipoic acid as lipid headgroup ( K a = 7 × 10 7 M −1 ) leads to formation of small snisotropic protein domains indicating a crystall…
Crystallization and preliminary X-ray analysis of W120K mutant of streptavidin.
2001
Bacterial streptavidin and chicken avidin are homotetrameric proteins that share an exceptionally high affinity towards the vitamin biotin. The biotin-binding sites in both proteins contain a crucial tryptophan residue contributed from an adjacent subunit. This particular tryptophan (W110 in avidin and W120 in streptavidin) plays an important role in both biotin binding and in the quaternary stabilities of the proteins. An intriguing naturally occurring alteration of tryptophan to lysine was previously described in the C-terminal domain of sea-urchin fibropellins, which share a relatively high sequence similarity with avidin and streptavidin. Avidin (Avm-W110K) and streptavidin (Savm-W120K)…
Surface-immobilized DNAzyme-type biocatalysis
2014
The structure of the double helix of deoxyribonucleic acid (DNA, also called duplex-DNA) was elucidated sixty years ago by Watson, Crick, Wilkins and Franklin. Since then, DNA has continued to hold a fascination for researchers in diverse fields including medicine and nanobiotechnology. Nature has indeed excelled in diversifying the use of DNA: beyond its canonical role of repository of genetic information, DNA could also act as a nanofactory able to perform some complex catalytic tasks in an enzyme-mimicking manner. The catalytic capability of DNA was termed DNAzyme; in this context, a peculiar DNA structure, a quadruple helix also named quadruplex-DNA, has recently garnered considerable i…
Specific Protein Binding to Functionalized Interfaces
1992
We report on the characterization of specific binding reactions between streptavidin and biotinylated model membrane surfaces. Self-assembly techniques as well as the Langmuir-Blodgett-Kuhn method were employed to prepare reactive, functionalized surfaces on various solid supports in contact with the aqueous protein solution. Plasmon surface polaritons optical measurements as well as atomic force microscopy and studies with the surface forces apparatus give rather detailed information as to the streptavidin monolayer formation, the kinetics of this process (either binding site- or diffusion limited), the selectivity of the reaction at laterally heterogeneous membranes, and the involved inte…
Functionalized lipid tubules as tools for helical crystallization of proteins
1997
The development of functional supramolecular devices built by self-assembly of elementary molecules and with bioactive properties arouses considerable interest in the field of nanotechnology and new materials. We report here the formation of a new class of lipid tubules exhibiting both properties of molecular recognition and crystal formation for the protein streptavidin. These lipid tubules, made of biotin-containing dioctadecylamine molecules, are straight hollow cylinders with a constant diameter of 27 nm and variable length up to several micrometers. They are unilamellar with an inner diameter of about 16 nm, as shown by cryoelectron microscopy. Streptavidin binds to the biotinylated tu…
Promotion of osteogenic cell response using quasicovalent immobilized fibronectin on titanium surfaces: introduction of a novel biomimetic layer syst…
2012
Purpose Despite the undeniable potential of cell adhesion molecules such as fibronectin to support osteogenic cell responses and consecutive dental implant healing, the most beneficial mode of application onto titanium implant surfaces still requires investigation. Unspecific fibronectin adsorption on titanium dioxide (TiO2) surfaces can result in low-loading, high-desorption rates and protein–metal interactions with impaired biologic activity. The aim of the present study was to monitor the osteogenic cell responses (cell adhesion, proliferation, and differentiation) specifically to fibronectin biofunctionalized TiO2. Materials and Methods An innovative biomimetic streptavidin-biotin layer…
A simple strategy based on photobiotin irradiation for the photoelectrochemical immobilization of proteins on electrode surfaces
2006
Abstract A photoactivable organic polymer was prepared first by electrogeneration of a conductive biotinylated polypyrrole film in acetonitrile electrolyte. The successive anchoring of avidin and photobiotin led to a multilayer configuration. The latter was illuminated with light (wavelength 370–400 nm) in the presence of proteins adsorbed onto its surface. The irradiation allowed the covalent linking of the proteins to the modified electrode. As a result of the photochemical reaction, a monolayer of enzyme (glucose oxidase, GOX or alkaline phosphatase, AP) was covalently bound to the photobiotin-modified surface with retention of their catalytic activities. The surfacic activities were 34 …
Purification by affinity chromatography of H1 RNA-Binding Proteins from rat brain
2003
Post-transcriptional regulation of mRNA metabolism is involved in processes as different as cell fate specification in development and cell response to a large variety of environmental cues. Regulation of all steps of RNA metabolism depends on RNA-binding proteins (RBPs). By using a T1 RNase protection assay, we previously identified three H1° RNA-binding factors (p40, p70 and p110), highly expressed in the rat brain. Here we report enrichment of these factors from brain extracts, obtained by affinity chromatography of biotinylated H1° RNA-protein complexes on streptavidin-conjugated paramagnetic particles. The purified proteins maintain RNA-binding ability and preference for histone messag…
Efficient gene therapy based targeting system for the treatment of inoperable tumors
2012
Background A considerable percentage of tumors are not amenable to surgery. We have designed a simple and powerful targeting system that offers an alternative option for the multi-component pre-targeting strategies used clinically. This targeting system can be used for any type of solid tumors independent of the tumor type, thereby omitting the need to engineer unique antibodies for each specific application or tumour type. In the present study, we show the expression of a chimeric fusion protein, which contains the low-density lipoprotein receptor transmembrane domains and avidin, after local gene transfer and its ability to bind biotinylated compounds in vivo. Methods Semliki Forest virus…
Thioredoxin-related protein of 14 kDa may directly reduce protein cysteinylation motifs
2018
Disulfide stress has been associated with inflammation and characterized by an increase in cystine levels and protein cysteinylation. Furthermore, it was recently discovered that thioredoxin-related protein of 14 kDa (TRP14, encoded by TXNDC17) exhibits efficient cystine reductase activity. The aim of our research was to elucidate if TRP14 is also able to reduce cysteinylated proteins in mammalian cells. Thus, protein cysteinylation was assessed in control and TRP14 knockdown cells in vitro through their pre-treatment with 25 µg/ml cycloheximide for 30 min and incubation with 250 µM biotinylated cysteine for 1 h. Moreover, such TRP14 knockdown cell lysates were tested as cysteinylated subst…