Search results for "streptavidin"

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…

Molecular cloning and nucleotide sequence of chicken avidin-related genes 1-5.

1994

Using avidin cDNA as a hybridisation probe, we detected a gene family whose putative products are related to the chicken egg-white avidin. Two overlapping genomic clones were found to contain five genes (avidin-related genes 1–5, avrl-avr5), which have been cloned, characterized and sequenced. All of the genes have a four-exon structure with an overall identity with the avidin cDNA of 88–92%. The genes appear to have no pseudogenic features and, in fact, two of these genes have been shown to be transcribed. The putative proteins share a sequence identity of 68–78% with avidin. The amino acid residues responsible for the biotin-binding activity of avidin and the bacterial biotin-binding prot…

Molecular Recognition of Biotinyl Hydrophobic Helical Peptides with Streptavidin at the Air/Water Interface

1994

Layer-by-layer assembled protein/polymer hybrid films: nanoconstruction via specific recognition

1998

Abstract In the present study it is shown that streptavidin-containing multilayer films with varying numbers of polyelectrolyte spacer layers can be fabricated reproducibly using optimized deposition conditions. Direct alternation of streptavidin and PLB leads to multilayer systems with an average streptavidin thickness of 5.3 nm which is in good agreement with the dimensions of the protein. When the streptavidin layers are spacered by more polyelectrolyte layers the distance between the protein sheets is increased up to e.g. 6.5 nm in the case of (PLB/PSS/PAH/PSS/PLB) as spacer layer. X-ray reflectivity reveals that streptavidin increases the surface roughness of the films probably due to …

Bilayer Formation of Streptavidin Bridged by Bis(biotinyl) Peptide at the Air/Water Interface

1994

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…

Ligand-receptor interactions directly measured with the surface forces apparatus

1991

Ligand-receptor interactions give rise to very strong bonds due to perfect geometrical fit. Using the Surface Forces Apparatus we have studied the interactions between membrane-bound biotin ligands and streptavidin receptors. We find an unusually strong short-range binding force associated with equally specific molecular rearrangements-both qualitatively and quantitatively unlike anything previously measured.

Protein-Membrane Interaction

2012

In the following chapter I present a nanosized and addressable protein sensor platform based on membrane coated plasmonic particles. I show unequivocally the covering of gold nanorods with lipid bilayers and thereafter the subsequent detection of streptavidin binding to biotin moities in the lipids. The binding of the streptavidin on the membrane covered gold nanorods is detected by monitoring the spectral shift by fast single particle spectroscopy (fastSPS) on many particles in parallel.

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…