Tumor imaging with labeled liposomes is slow; although they reach the tumor quickly, their blood clearance is slow, and the high blood background hinders early imaging. We have developed a rapid tumor imaging technique based on the active removal of liposomes from the circulation by using the avidin-biotin system. 67Ga- or 111In-labeled liposomes with biotin molecules bound on the surface were ...

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...

We studied the specific labeling of streptavidin using the modular method for affinity labeling (MoAL) that we developed based on a catalytic amide-forming reaction using 2-chloro-4,6-dimethoxy-1,3,5-triazine (CDMT) and a tertiary amine catalyst. The primary structures of avidin and streptavidin are significantly different from each other, and streptavidin does not possess an acidic amino acid ...

A method of enriching for long double-stranded segments of eukaryotic DNA carrying particular genes is described. A purified RNA coded for by the gene is covalently attached to biotin via the protein, cytochrome c. This modified RNA is hybridized to total nuclear, double-stranded DNA under conditions that allow the formation of R-loops. Avidin, which has a high affinity for biotin, is covalentl...

Human apurinic/apyrimidinic endonuclease/redox effector factor 1 (APE1) is an essential DNA repair protein. Herein, we demonstrate that avidin-oriented abasic site-containing DNA strands (AP-DNA) on the surface of silica coated magnetic nanoparticles (SiMNP) can selectively respond to APE1 while resist the digestion by other nucleases. Mechanism studies have revealed that avidin may serve as an...

Multicomponent crystals and nanoparticle superlattices are a powerful approach to integrate different materials into ordered nanostructures. Well-developed, especially DNA-based, methods for their preparation exist, yet most techniques concentrate on molecular and synthetic nanoparticle systems in non-biocompatible environment. Here we describe the self-assembly and characterization of binary s...

We describe a general method for incorporating target ligands into the surface of biocompatible polyester poly(lactic-co-glycolic acid) (PLGA) 50/50 materials using fatty acids. Avidin-fatty acid conjugates were prepared and efficiently incorporated into PLGA. Avidin was chosen as an adaptor protein to facilitate the attachment of a variety of biotinylated ligands. We show that fatty acid prefe...

Streptavidin, the non-glycosylated bacterial analogue of the egg-white glycoprotein avidin, was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl (Hnb) bromide. As with avidin, complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per streptavidin subunit. Tryptic peptides obtained from an Hnb-modified streptavidin pr...

We have developed a general procedure for the rapid and efficient enrichment of specific DNA, RNA or cDNA sequences. Biotinylated DNA or RNA is used as a hybridization probe in solution, avidin is then added to label both the probe and hybrid molecules, and the hybridization mixture chromatographed over cupric-iminodiacetic acid agarose beads. Avidin-probe and avidin-hybrid molecules are select...