Dendrimers are highly customizable nanopolymers with qualities that make them ideal for drug delivery. The high binding affinity of biotin/avidin provides a useful approach to fluorescently label synthesized dendrimer-conjugates in cells and tissues. In addition, biotin may facilitate delivery of dendrimers through the blood-brain barrier (BBB) via carrier-mediated endocytosis. The purpose of t...

After the intravenous infusion of N-hydroxysuccinimido biotin into dogs, 80.6% +/- 9.7% (n = 5) of platelets were covalently labeled with biotin. The in vivo survival of the biotinylated platelets was monitored by flow cytometry and was normal as compared with previous reports for dog platelets. The ability of the biotinylated platelets to be activated was analyzed by measuring the expression o...

Membrane trafficking involves transport of proteins from the plasma membrane to the cell interior (i.e. endocytosis) followed by trafficking to lysosomes for degradation or to the plasma membrane for recycling. The cell based L-glutathione protection assays can be used to study endocytosis and recycling of protein receptors, channels, transporters, and adhesion molecules localized at the cell s...

The effect of avidin-biotin interactions in several detection systems for the non-radioactive in situ hybridization (ISH) technique was studied in a model system using a transitional cell carcinoma line and a biotinylated DNA probe. We performed fluorescence ISH to unravel the individual steps in a sensitive and frequently used amplification method which makes use of the alternating cytochemica...

Biotin-dependent carboxylases are ubiquitous enzymes necessary for a variety of anabolic and catabolic pathways. In plants, six biotinylated polypeptides have been detected (Wurtele and Nikolau, 1990), and four biotin-dependent carboxylase enzymes have been demonstrated: acetyl-COA carboxylase (Egli et al., 1993, and refs. therein), MCCase, pyruvate carboxylase, and propionyl-COA carboxylase (W...

A biotinylated derivative of alpha-bungarotoxin and tetramethylrhodamine-labeled avidin were employed to fluorescence label the acetylcholine receptors (AcChoR) on the surface of rat myotubes in primary culture. Because of the multivalency of both the biotinylated bungarotoxin and the avidin, this treatment extensivey crosslinks the AcChoR. AcChoR crosslinking immobilizes more than 90% of the n...

Two biotinylated derivatives of the fungal metabolite galiellalactone (1) were synthesized in order to facilitate the investigation of the molecular mechanism of action of the galiellalactonoids. Galiellalactone is a STAT3-signaling inhibitor that inhibits growth in vitro as well as in vivo of prostate cancer cells expressing activated STAT3. To provide a suitable point of attachment for biotin...