A homogeneous enzyme-linked competitive-binding assay for biotin with glucose-6-phosphate dehydrogenase (GGPDH), is described. This assay is based on the interaction between a GGPDH/biotin conjugate with avidin, a natural binder for biotin. In the absence of biotin in the assay mixture, this interaction results in 100% inhibition of the enzyme conjugate. In the presence of biotin, the enzymatic...

A modification of previously described methods of electron microscopic gene mapping and of gene enrichment based on the avidin-biotin interaction is presented. The modification consists of coupling cytochrome-c instead of pentane diamine to the oxidized 2', 3' terminus of an RNA by Schiff base formation and BH-4 reduction. The RNA-cytochrome-c conjugate is purified by a simple chromatographic p...

Avidin transgenic plants are a potential tool for providing resistance against various species of insect pests due to the sequestration of vitamin H (biotin) in the plant from the insect pests. In this project we compared three techniques for avidin determination in transgenic tobacco plants, a novel chip-based capillary electrophoretic method (Experion), classical polyacrylamide gel electropho...

Protein nanowires exhibiting specific biological activities hold promise for interacting with living cells and controlling and predicting biological responses such as apoptosis, endocytosis and cell adhesion. Here we report the result of the interaction of a single high-energy charged particle with protein molecules, giving size-controlled protein nanowires with an ultra-high aspect ratio of ov...

The preparation of a reagent which can be used to attach biotin to proteins via a cleavable connector arm is described. The reagent, 3-(4-(N-biotinoyl-6-aminocaproyloxy)phenyl)propionic acid N-hydroxysuccinimide ester (BPE), can acylate amino groups of proteins and other compounds via reaction of the N-hydroxysuccinimide ester function. Compounds which have been covalently labeled with BPE can ...

Poliovirus-specific double-stranded RNA molecules containing covalently attached protein were coupled with a biotin ester through the protein moiety. Subsequent interaction of the RNA-biotin with avidin attached to electronopaque plastic spheres led to the formation of complexes that were easily visualized in the electron microscope. Avidinspheres were associated only with one end of the RNA-bi...

Several cell lines were evaluated for their suitability for rapid detection of herpes simplex virus (HSV) from clinical genital specimens. Human foreskin fibroblast (Flow 7000) cells were found to be most suitable in terms of sensitivity and adherence characteristics. HSV in clinical specimens was isolated by a standard tissue culture method by monitoring the cytopathic effect, and the titers o...

Local drug delivery into cartilage remains a challenge due to its dense extracellular matrix of negatively charged proteoglycans enmeshed within a collagen fibril network. The high negative fixed charge density of cartilage offers the unique opportunity to utilize electrostatic interactions to augment transport, binding and retention of drug carriers. With the goal of developing particle-based ...

Vol. 40, No. 5 (2006) The binding of avidin to biotin is the strongest known noncovalent biological interaction [dissociation constants (Kd) approximately 10 -15 M] between a protein and ligand (1). The high affinity and specificity of the avidin-biotin interaction is utilized for enriching biotin-containing proteins from mixtures (2,3). Water-soluble Nhydroxysulfosuccinimide (sulfo-NHS) deriva...

We report on the fabrication of well-defined polymer-protein bioconjugates with varying chain architectures, including star polymers, star block copolymers, and heteroarm star copolymers through the specific noncovalent interaction between avidin and biotinylated synthetic polymer precursors. Homopolymer and diblock precursors site-specifically labeled with a single biotin moiety at the chain t...