The lanthanide binuclear helicate [Eu(2)(L(C2(CO(2)H)))(3)] is coupled to avidin to yield a luminescent bioconjugate EuB1 (Q = 9.3%, tau((5)D(0)) = 2.17 ms). MALDI/TOF mass spectrometry confirms the covalent binding of the Eu chelate and UV-visible spectroscopy allows one to determine a luminophore/protein ratio equal to 3.2. Bio-affinity assays involving the recognition of a mucin-like protein...

The high-affinity binding of biotin to avidin, streptavidin, and related proteins has been exploited for decades. However, a disadvantage of the biotin/biotin-binding protein interaction is that it is essentially irreversible under physiological conditions. Desthiobiotin is a biotin analogue that binds less tightly to biotin-binding proteins and is easily displaced by biotin. We synthesized an ...

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...

Background: The chicken genome contains a BBP-A gene showing similar characteristics to avidin family genes. In a previous study we reported that the BBP-A gene may encode a biotin-binding protein due to the high sequence similarity with chicken avidin, especially at regions encoding residues known to be located at the ligand-binding site of avidin. Results: Here, we expand the repertoire of kn...

Recent work has demonstrated the feasibility of employing three dimensional (3D) protein hydrogels, fabricated using multiphoton-induced photochemistry, as chemically responsive microactuators in ‘‘lab on a chip’’ devices. In addition, these materials show great promise as cell capture/incubation devices, allowing single bacterial cells to reproduce into multicellular constructs with ‘‘user-def...

Fluorescence enhancement was studied on silver colloidal metal films (CMFs) using two systems: (1) Langmuir--Blodgett monolayers of fluorescein-labeled phospholipids separated from the surface of the films by spacer layers of octadecanoic acid and (2) biotin--fluorescein conjugates captured by avidin molecules adsorbed on top of a multilayer structure formed by alternating layers of bovine seru...

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...

In the chick oviduct, injections of estrogen and progesterone induce synthesis of the specific proteins ovalbumin and avidin, respectively. We have studied the rate of induction of the specific messenger RNA molecules for these proteins after a single injection of estrogen or progesterone. The mRNAs were extracted, partially purified, and quantified in vitro in a heterologous protein-synthesizi...