Streptavidin is a tetrameric protein produced by the bacterium Streptomyces avidinii; it has great similarity to the chicken protein avidin.14 These proteins bind the vitamin biotin with an extremely high affinity. The dissociation constant of streptavidin-biotin and avidin-biotin complexes is estimated at around M;3.4 this is one of the tightest noncovalent interactions found in biological sys...

To expand the electron microscopist's options in localization and visualization, a new and general staining technique has been tested. The avidin-biotin complex serves as a coupling between the electron-dense marker, ferritin, and points of interest in biological samples. When specific cellular components are tagged with biotin, those components may be visualized with ferritin-linked avidin. Be...

In the present study a novel Ab-avidin fusion protein has been constructed to deliver biotinylated compounds across the blood brain barrier. This fusion molecule consists of an Ab specific for the transferrin receptor genetically fused to avidin. The Ab-avidin fusion protein (anti-TfR IgG3-CH3-Av) expressed in murine myeloma cells was correctly assembled and secreted and showed both Ab- and avi...

Several biotinyl estradiol derivatives have been prepared by coupling estradiol 7 alpha-carboxylic acid to biotin via different linear linkers. All these compounds exhibit a high affinity for the estrogen receptor as determined by competitive binding assays against [3H]estradiol. These compounds also displaced the dye 4-hydroxyazobenzene-2'-carboxylic acid from the biotin-binding sites of avidi...

We prepared self-assembled vesicles comprising layers of fullerene, alkyl chains, triazole, oligo(ethylene oxide) chains, biotin and avidin molecules. High-resolution scanning electron microscopy using a superhydrophilic indium-tin oxide substrate was found to be useful for nanometer-level structural analysis of the vesicles and individual avidin molecules whose structures are difficult to anal...

An improved purification, including crystallization, of avidin from hen's-egg white is described. The product bound 15.1mug of biotin/mg, corresponding to an equivalent weight of 16200. The amino acid composition showed an integral number of amino acid residues per 16200g, which suggested that each molecule of avidin (mol. wt. approx. 66000) contained four identical subunits.

Excitation-contraction coupling in skeletal muscle involves conformational coupling between dihydropyridine receptors (DHPRs) in the plasma membrane and ryanodine receptors (RyRs) in the sarcoplasmic reticulum. However, it remains uncertain what regions, if any, of the two proteins interact with one another. Toward this end, it would be valuable to know the spatial interrelationships of DHPRs a...

Fourier-transform infrared studies have been carried out to investigate the secondary structure and thermal stability of hen egg white avidin and its complexes with biotin and with a biotinylated lipid derivative, N-biotinyl dimyristoyl phosphatidylethanolamine (DMBPE) in aqueous dispersion. Analysis of the amide I stretching band of avidin yielded a secondary structural content composed of app...

Localization of ganglioside GM1 in cholinergic neurons from the septal area of a primary culture newborn rat brain was studied with a double avidin-biotin complex system. Cholinergic neurons were identified by double immunolabeling techniques that use choline acetyltransferase (ChAT) and neurofilament (NF) protein-antibodies. ChAT-positive neurons also were stained for ganglioside GM1 by using ...

Fourier-transform infrared studies have been carried out to investigate the secondary structure and thermal stability of hen egg white avidin and its complexes with biotin and with a biotinylated lipid derivative, N-biotinyl dimyristoyl phosphatidylethanolamine (DMBPE) in aqueous dispersion. Analysis of the amide I stretching band of avidin yielded a secondary structural content composed of app...