Cell membrane glycoprotein

Glycohpids (5,14) are primarily glycosphingoHpids, molecules that have oligosaccharide groups attached to ceramide [104404-17-3]. They are present, at least in small amounts, in the membranes of most, if not all, tissues. They too, like cell-membrane glycoproteins, are recognition deterrninants. 

The amiloride-sensitive Na+ channel (ENaC) is a cell membrane glycoprotein selective for sodium ions, which is composed of three subunits (a, (3 and y). Gating of sodium is inhibited by the diuretic amiloride. 

O-Linked Oligosaccharide Chains of Serum and Cell-Membrane Glycoproteins... 

The monoclonal antibody, BER-EP4 (32), recognizes a cell membrane glycoprotein consisting of two polypeptide chains (mol wt 34 kD and 39 kD). Its... 

Hessle L, Johnson KA, Anderson HC, Narisawa S, Sali A, Coding JW, Terkeltaub R, Millan JL. 2002. Tissue-nonspecific alkaline phosphatase and plasma cell membrane glycoprotein-1 are central antagonistic regulators of bone mineralization. Proc Natl Acad Sci USA 99 9445—9. 

Integrins Cell membrane glycoproteins that function as receptor for extracellular... 

Transferrin Receptor. Transferrin receptor is a cell membrane glycoprotein that binds to transferrin to transport iron ion into cells by receptor-mediated endocytosis. Human transferrin receptors are overexpressed... 

A physiologic phosphate concentration is required for bone mineralization. Lowering the concentration prevents mineralization, but raising it does not ensure precipitation because pyrophosphate is present to inhibit precipitation. The concentration of PPi in cartilage and bone is controlled by three enzymes, two on the outer surface of matrix vesicles (Fig. 9.5b). One is tissue-nonspecific alkaline phosphatase (TNAP), which decreases stromal pyrophosphate and the other is NTP-PPi hydrolase (also called plasma cell membrane glycoprotein-1), which increases it. The progressive ankylosis gene product (ANK protein) is expressed by osteoblasts to add to the pyrophosphate of the osteoid matrix from osteoblast cytosol. 

Fig.9.8 Removal of pyrophosphate is necessary for precipitation. Pyrophosphate (PPi) inhibits the precipitation of calcium phosphate. In the bone matrix, PC-1 (red) is the major producer of PPi from nucleotide triphosphates (NTPs, thick arrow on left) and ANK is a minor producer by transporting it from the cytosol of osteoblasts. TNAP (green) causes mineralization by its phosphatase activity converting PPi to two molecules of Pi. TNAP also generates Pi directly from NTPs and PPi, but most Pi and most Ca2+ are derived directly from the diet (thick arrow on right) (Slightly modified from Fig. 4 in Hessle L et al. (2002) Tissue-nonspecific alkaline phosphatase and plasma cell membrane glycoprotein-1 are central antagonistic regulators of bone mineralization. Proceedings of the National Academy of Sciences 99 9445-9449. Copyright (2002) National Academy of Sciences, U.S.A)...

Johnson K, Moffa A, Chen Y et al (1999) Matrix vesicle plasma cell membrane glycoprotein-1 regulates mineralization by mimne osteoblastic MC3T3 cells. J Bone Miner Res 14 883-892... 

Ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPPl), also known as plasma cell membrane glycoprotein 1 (PC-1), is a member of the NPP family of transmembrane enzymes that catalyzes the hydrolysis of extracellular nucleotides. Different family members demonstrate preference for distinct substrates, but share ability to hydrolyze phosphodiester and pyrophosphatase bonds [1]. ENPPl appears to have preference for ATP, but also demonstrates pyrophosphatase and phosphodiesterase activities toward pyrophosphate and ADP [1, 2],... 

Peltz, G., et al. (1987). Monoclonal Antibody Immunoprecipitation of Cell Membrane Glycoproteins, Anal. Biochem. 167 239-244. 

The following aspects of viral glycoproteins have been reviewed glycoprotein and protein precursors to plasma membranes in vesicular stomatitis virus infected HeLa cells,membrane glycoproteins of enveloped viruses, membrane assembly, including the synthesis and intracellular processing of vesicular stomatitis virus, and the structure and replication of a-viruses. ... 

A mechanical device for the continuous purification of biological material using an immunoadsorbent has been described.The use of immobilized lectins in affinity chromatography has been discussed,and the purification of cell-membrane glycoproteins on columns of immobilized lectins reviewed. New teehniques of cell fractionation involving use of immobilized lectins or selective agglutination with leetins have been described. ... 

Hynes RO (2004) The emergence of integrins a personal and historical perspective. Matrix Biol 23 333-340 Ino Y, Gotoh M, Sakamoto M et al (2002) Dysadherin, a cancer-associated cell membrane glycoprotein, down-regu-lates E-cadherin and promotes metastasis. Proc Natl Acad Sci USA 99 365-370... 

---