Transmembrane receptor protein

The non-specific interaction of amlodipine with the membrane may thus lead to a defined and specific location, orientation, and conformation required for binding to a transmembrane receptor protein. It may help to understand and explain its pharmacodynamic and pharmacokinetic profile, which shows a slow onset and a long duration of activity compared with uncharged drugs of this class [95]. 

Stora T, Lakey JH, Vogel H. Ion-channel gating in transmembrane receptor proteins Functional activity in tethered lipid membranes. Angew. Chem. Int. Ed. 1999 38 389-392. 

Figure 15 Transferrin-mediated iron uptake by bacteria. One lobe of ferric transferrin binds to the OM transmembrane receptor protein TbpA TbpB facilitates bmdmg.The unchelated ferric ion passes through the membrane and is then bound by the ferric-binding protein (FbpA), located in the periplasm. A TonB-ExbBD-like protein system provides the energy required for this process. FbpA shuttles the iron to the CM transmembrane protein FbpB. The iron moves into the cytoplasm following hydrolysis of ATP by FbpC.

Most cholesterol Is transported In Ihe blood bound to protein in Ihe form of particles known as low-density lipoproteins, or LDL (Figure 13-29t. When a cell needs cholesterol for membrane synthesis, it makes transmembrane receptor proteins for LDL and inserts them Into Its plasma membrane. Once In the plasma membrane, the LDL receptors diffuse until they associate with clathrin-coated pits that are In the process of forming (Figure 13-30AL Since coated pits constantly pinch off to form coated vesicles, any LDL particles bound to LDL receptors in the coated pits are rapidly Internalized In coated vesicles. After shedding their clathrin coats, these vesicles deliver their contents to early endosomes. which are located near the cell... 

The B-cell receptor (BCR), a transmembrane receptor protein on the outer surface of B-cells, initiates the BCR pathway regulating several essential cellular processes including proliferation, differentiation, and apoptosis, which are critical for the functions and survival of both normal and malignant B cells.The BCR pathway involves multiple protein tyrosine kinases (PTKs), such as Lyn, Syk, and Bruton s tyrosine kinase (Btk). These PTKs have been found to be constitutively active and/or overexpressed that lead to uncontrolled proliferation and survival of malignant B cells. Btk, a kinase in the Tec family, is a unique therapeutic target. Upon BCR activation, Btk becomes activated by other PTKs, such as Lyn and/or Syk, resulting in activation of downstream events necessary for B-cell proliferation and differentiation. Inhibition of Btk activity prevents... 

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