Elucidating the mechanism of cellular uptake and removal of protein Adult people finder online dating
In the case of antagonist-modified particles, the fluorescence was strictly limited to the cell membrane, indicating that particles were located on the cell surfaces only (-receptor–positive cell line derived from the central nervous system (Fig. This result clearly demonstrates that the findings are neither dependent upon the cell type nor the receptor density [SK-N-MC cells: ≈60,000 receptors per cell (21); MCF-7 cells: ≈300,000 receptors per cell (21)].In summary, our results show that GPCRs can be used to target nanoparticles specifically either to the target cell's surface or to its intracellular compartment by simply attaching an antagonist or an agonist, respectively, to the particle surface. This multiligand binding leads to five orders of magnitude increased-receptor affinities, compared with free ligand, in displacement studies. We found that agonist- and antagonist-modified nanoparticles bind to several receptor molecules at a time.We found that agonist- and antagonist-modified nanoparticles bind to several receptor molecules at a time. Having identified such a potential “molecular switch” for controlling the gateway into cells, we hypothesized that the immobilization of an agonist on a nanoparticle surface would cause cellular uptake, although the immobilization of an antagonist to a particle would result in arrest on the cell surface.This multiligand binding leads to five orders of magnitude increased-receptor affinities, compared with free ligand, in displacement studies. Furthermore, we believed that such nanoparticles will preserve their high cell affinity and target specifity by attaching to cell surface receptors via a multiligand binding mode.
Using MCF-7 breast cancer cells expressing the human Y(1)-receptor, we demonstrate that G protein-coupled receptors provide us with this option. The family of G protein-coupled receptors (GPCRs), which exhibit high tissue specificity and represent the largest class of receptors in the human genome (11), appeared to be a promising choice.
Similarly, QDs decorated with a low molecular mass, nonpeptidic antagonist were prepared.
For the attachment to the QDs, a thiol was introduced into the antagonist BIBP3226 by acylation with 6-mercaptohexanoic acid to obtain (R)-N) Scheme of the bioconjugation reaction.
Using MCF-7 breast cancer cells expressing the human Y-receptor, we demonstrate that G protein-coupled receptors provide us with this option.
To date no class of targets is known that would allow direction of nanoparticle interactions with cells alternatively into one of these mutually exclusive events.
After activation of the amino-PEG QDs (1) with sulfo-SMCC, the resulting thiol-reactive nanoparticles (2) were connected with either the peptidic agonistic analogs of p NPY or the nonpeptidic antagonist SH-BIBP to yield the ligand-modified QDs (3).