Protein cell-associated

Magid et al. (Ml) recently explored the regulation of MMPs in endothelial cells exposed to shear stress. They reported that oscillatory blood flow, but not unidirectional shear, significantly increased MMP-9 mRNA as well as cell secretion of MMP-9 protein. Cell associated TIMP-1 was insensitive to the shear regimen. They demonstrated that the c-Myc transcriptional factor binds specifically to a site in the MMP-9 promoter. This effect may contribute to the progression of atherosclerosis. 

Figure 7.12 Effect of pore size on the production of total glycosaminoglycan (CAC) protein (cell associated released into the medium) by chondrocytes cultured on various pore-sized hydroxylapatite-coated 2EHA/styrene (copolymer) poly HI PE polymer after 21 days in culture...

Figure 2. Mechanism of PDH. The three different subunits of the PDH complex in the mitochondrial matrix (E, pyruvate decarboxylase E2, dihydrolipoamide acyltrans-ferase Ej, dihydrolipoamide dehydrogenase) catalyze the oxidative decarboxylation of pyruvate to acetyl-CoA and CO2. E, decarboxylates pyruvate and transfers the acetyl-group to lipoamide. Lipoamide is linked to the group of a lysine residue to E2 to form a flexible chain which rotates between the active sites of E, E2, and E3. E2 then transfers the acetyl-group from lipoamide to CoASH leaving the lipoamide in the reduced form. This in turn is oxidized by E3, which is an NAD-dependent (low potential) flavoprotein, completing the catalytic cycle. PDH activity is controlled in two ways by product inhibition by NADH and acetyl-CoA formed from pyruvate (or by P-oxidation), and by inactivation by phosphorylation of Ej by a specific ATP-de-pendent protein kinase associated with the complex, or activation by dephosphorylation by a specific phosphoprotein phosphatase. The phosphatase is activated by increases in the concentration of Ca in the matrix. The combination of insulin with its cell surface receptor activates PDH by activating the phosphatase by an unknown mechanism.

Singh, N.K., La Rosa, P.C., Handa, A.K., Hasegawa, P.M. Bressan, R.A. (1987f>). Hormonal regulation of protein synthesis associated with salt tolerance in plant cells. Proceedings of the National Academy of Sciences, USA, 84,739-43. 

Hodgkinson, C. A Moore, K. J., Nakayama, A., Steingrimmsson, E., Copeland, N. G., Jenkins, N. A., and Amheiter, H. (1993). Mutations at the mouse microphthalmia locus are associated with defects in a gene encoding a novel basic-helix-loop-he-lix-zipper protein. Cell 74 395-404. 

Transport of MBOs to their various destinations is typically mediated by MTs and motor molecules. Membrane and secretory proteins become associated with membranes either during or immediately following their synthesis, and then maintain this association throughout their lifetime in the cell. For example, inhibiting synthesis of either protein or phospholipid leads to a proportional decrease in the amount of both protein and phospholipid... 

In addition to the above extracellular parameters, cell concentration and cell activity are two important cell-associated parameters that determine how well a fermentation process is performing. The manufacturing of biological products (antibiotics, amino acids, monoclonal antibodies, and other protein products) at large scales requires that cells be cultured at high cell densities and stay metabolically active. Consequently, much effort has been expended to develop techniques that can allow the estimation of cell concentration and cell activity in real time during a fermentation. 

To study the effect of the protease treatment cell-free suspension, with or without protease treatment, was subjected to gel-filtration chromatography on Sephadex G-75 and the elution patterns were compared (Fig. 1). In each case, two major peaks were detected by monitoring column fractions with absorbance at 280 nm. Degradation activities on mexacarbate, in the presence of FMN and light under anaerobic condition, were measured for each fraction. It was found that the highest activity was associated with peak II. It is interesting to note that protein (s) associated with peak II were detected with or without protease treatment these will be referred to as natural flavoprotein (B, Fig. 

Herceptin attaches to the HER2/neu receptor and activates the complement system (a series of serum and cell-associated proteins involved in immune response) to destroy those cells expressing such receptors. Through this action, Herceptin disrupts the signaling pathway for breast cancer cell proliferation (refer to diagram below). 

Khanuja PS, Lehr JE, Soule HD, Gehani SK, Noto AC, Choudhury S, Chen R, Pienta KJ (1993) Nuclear matrix proteins in normal and breast cancer cells. Cancer Res 53(14) 3394-3398 Konety BR, Nangia AK, Nguyen T.S, Veitmeier BN, Dhir R, Acierno JS, Becich MJ, Hrebinko RL, Getzenberg RH (1998) Identification of nuclear matrix protein alterations associated with renal cell carcinoma. J Urol 159(4) 1359-1363... 

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