Protein-based drug delivery carrier has been one of the most employed modalities in biopharmaceuticals. In this study, we have compared avidin and its two analogues, neutravidin and streptavidin, as nanocarriers for the delivery of biotin-labeled siRNA with the help of biotinylated cholesterol (targeting ligand) and protamine (condensing agent). These proteins have similar binding affinity to b...

The binding of aniohic dyes by serum albumin has been studied by many workers (reviewed by Foster, 1960). The evidence suggests several cationic sites situated in hydrophobic regions of the molecule. For example, the bound dye shows spectral changes that are in accord with its location in a non-polar environment. Since it was suggested (Green, 1963b) that the biotin-binding sites of avidin were...

The metabolic control of biotin transport in Saccharomyces cerevisiae was investigated. Nonproliferating cells harvested from cultures grown in excess biotin (25 ng/ml) took up small amounts of biotin, whereas cells grown in biotin-sufficient medium (0.25 ng/ml) accumulated large amounts of the vitamin. Transport was inhibited maximally in cells grown in medium containing 9 ng (or more) of biot...

In the course of studies on the ultrastructural localization and functions of contractile proteins in nonmuscle cells, we have found it useful to adapt the avidin-biotin complex technique introduced by Hei tzmann and Richards (7) to the specific labeling of actin and myosin components in these cells. These authors modified cell surfaces by covalent attachment of biotinyl residues, and then visu...

Coadsorption of high-affinity avidin with lower affinity cell adhesion protein fibronectin has been shown to significantly augment short-term (1 h) adhesion and spreading of endothelial cells; however, the longer term persistence of avidin binding and its effect on endothelial cell adhesion have not been addressed. In this study, the presence of avidin-biotin bonds 24 h after cell adhesion to t...

Avidin enhances the hydrolysis of biotinyl p-nitrophenyl ester (BNP) under mild alkaline conditions, whereas streptavidin prevents hydrolysis of BNP up to pH 12. Recently, we imposed hydrolytic activity on streptavidin by rational mutagenesis, based on the molecular elements responsible for the hydrolysis by avidin. Three mutants were designed, whereby the desired features, the distinctive L124...

Catalytic activity of the filamentous polymeric form of avian liver acetyl-CoA carboxylase, (spO+ = 45 to 47 S) undergoes first-order decay in assay reaction mixture (f; 10 min at Z”), which is rapidly reversed ( <lO s) by addition of tricarboxylic acid activator, i.e. citrate or isocitrate. As previously shown by sucrose density gradient centrifugation, extended exposure to assay reaction mixt...

The tumor-associated glycolipid, ganglio-N-triosylceramide (GaMAcS1 + 4GalSl -+ 4GlcPl 3 1Cer; GgOseaCer) was used as a target for antibody-conjugated drug killing of tumor cells. Because of antibody inactivation by drug conjugation, targeting systems have been developed in which administration of biotinyl-anti-glycolipid antibodies was followed by successive addition of: (a) avidin and biotiny...