Cell Molecular organization

Interfaces between two different media provide a place for conversion of energy and materials. Heterogeneous catalysts and photocatalysts act in vapor or liquid environments. Selective conversion and transport of materials occurs at membranes of biological tissues in water. Electron transport across solid/solid interfaces determines the efficiency of dye-sensitized solar cells or organic electroluminescence devices. There is hence an increasing need to apply molecular science to buried interfaces. 

From the atomic to the macroscopic level chirality is a characteristic feature of biological systems and plays an important role in the interplay of structure and function. Originating from small chiral precursors complex macromolecules such as proteins or DNA have developed during evolution. On a supramolecular level chirality is expressed in molecular organization, e.g. in the secondary and tertiary structure of proteins, in membranes, cells or tissues. On a macroscopic level, it appears in the chirality of our hands or in the asymmetric arrangement of our organs, or in the helicity of snail shells. Nature usually displays a preference for one sense of chirality over the other. This leads to specific interactions called chiral recognition. 

The method of pure polymer recovery from the biomass prior to characterization can influence the molecular weight of the polymer significantly. Extraction of PHB-bacterial cells with organic solvents yields polymers with higher molecular weight compared to sodium hypochorite treatment [44-46]. Pretreatment of the biomass with a surfactant prior to hypochlorite digestion... 

Yet another family of junction adhesion molecules (JAMs) was recently located at the tight junctions of both endothelial and epithelial cells. The intracellular domain of JAM-1 also interacts with structural and signaling proteins, such as ZO-1 and cingulin. Lastly, the molecular organization of the endothelial cell junctions includes two other cell-cell contact Ca2+-dependent cadherin-catenin systems. These make up the adherens junction common to all endothelial cell junctions. 

Preissner, K.T., Kanse, S.M., and May, A.E. 2000. Urokinase receptor a molecular organizer in cellular communication. Current Opinion in Cell Biology 12(5), 621-628. 

Kopplow, K., Letschert, K., Konig, J., Walter, B. and Keppler, D. (2005) Human hepatobiliary transport of organic anions analyzed by quadruple-transfected cells. Molecular Pharmacology, 68, 1031-1038. 

Caco-2 cells have been valuable in the estimation of drug absorption potential, transport mechanisms, and effect of permeation enhancers on transepithelial transport.35,39,53,67-69,78-81 Owing to the sensitivity of the cells and the limited solubility of new molecular entities, Caco-2 permeability studies are routinely done with relatively low concentration of compounds. One way to increase the solubility of these compounds is to use organic solvents. The low tolerability of Caco-2 cells to organic solvents limits the use of this approach in permeability studies. 

Stewart, P.L., Burnett, R.M., Cyrlaff, M., et al. (1991). Image reconstruction reveals the complex molecular organization of adenovirus. Cell, 67, 145-154. 

FIGURE 1-11 Structural hierarchy in the molecular organization of cells. In this plant cell, the nucleus is an organelle containing several types of supramolecular complexes, including chromosomes. Chro-... 

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