Mammalian small molecule-protein

Caligiuri M, Molz L, Liu Q, Kaplan F, Xu JP, Majeti JZ, Ramos-Kelsey R, Murthi K, Lievens S, Tavernier J, Kley N. MASPIT three-hybrid trap for quantitative proteome fingerprinting of small molecule-protein interactions in mammalian cells. Chem. Biol. 2006 13 711-722. 

Extracellular ligands (hormones, neurotrophins, carrier protein, adhesion molecules, small molecules, etc.) will bind to specific transmembrane receptors. This binding of specific ligand induces the concentration of the receptor in coated pits and internalization via clathrin-coated vesicles. One of the best studied and characterized examples of RME is the internalization of cholesterol by mammalian cells [69]. In the nervous system, there are a plethora of different membrane receptors that bind extracellular molecules, including neurotrophins, hormones and other cell modulators, being the best studied examples. This type of clathrin-mediated endocytosis is an amazingly efficient process, capable of concentrating... 

Figure 4 Examples of mimics of ligands and receptors used to deliver cargo into cells. (a,b) Ligands such as folate can be linked to macromolecules (e.g., nucleic acids and proteins) and small molecules (e.g., drugs, radiochemicals, and fluorophores) to promote cellular uptake, (c) Peptides and small molecules linked to N-alkyl derivatives of 3p-cholesterylamine or 3p-dihydrocholesterylamine mimic cell-surface receptors by cycling rapidly between the plasma membrane and the intracellular endosomes. The synthetic Fc receptor shown in (c) enables treated mammalian cells to internalize human igG.

---