Proteoglycans folding

Specific differences to note are a 10-fold lower level of histamine in the mucosal mast cell and the occurrence of distinct proteases and proteoglycans and (possibly) a different arachidonic acid metabolism for each type (55). These differences are sufficiently great to conclude that extrapolation of data on PMC (on which most research has been carried out) to MMC would be unwise. 

Scott PG, Dodd CM, Bergmann EM, Sheehan JK, Bishop PN. Crystal structure of the biglycan dimer and evidence that dimerization is essential for folding and stability of class I small leucine-rich repeat proteoglycans. J Biol Chem 2006 281 13324-13332. 

R 574 H. Schwalbe, Kurt Wuethrich, the ETH Zurich, and the Development of NMR Spectroscopy for the Investigation of Structure, Dynamics, and Folding of Proteins , ChemBioChem, 2003,4,135 R 575 J. E. Scott, Elasticity in Extracellular Matrix Shape Modules of Tendon, Cartilage, etc. A Sliding Proteoglycan-Filament Model , J. Physiol, 2003, 553, 335... 

It is known that when hepatocytes are freshly isolated and cultured under conventional conditions on plastic or collagen coated dishes, gene transcription is drastically depressed and liver specific mRNA declines while the mRNA of structure related genes increases many fold. By contrast, hepatocyte culture on extracellular matrix (ECM), rich in laminin, type IV collagen, and heparin sulfate proteoglycan exhibits increased longevity and maintenance of several liver-specific functions. 

Proteins and proteoglycans are important stabilisers of emulsions and foams in many food and non-food applications [3]. The interactions between protein molecules, either when adsorbed at interfaces or when present in the bulk, are very complex and are connected with changes in the conformation of the folded polypeptide chains. These changes have a wide range of characteristic time-scales [4]. When these particular features of proteins are superimposed on the above picture of a deformed interfacial film it is seen that the task of understanding the mechanism of action of proteins as surfactants is a daunting task. 

Figure 2.13 Participation of hyaluronan in formation of supramolecular complexes of proteoglycan aggregate. C 7, C2 and C3 are globular folded regions of the central core protein [41 ]. Reproduced from [4 7]. International Labor Office, Geneva...

Heparan sulfate proteoglycans and the coreceptors have been localized predominantly to the basolateral surface of WD HAE cells (47), which correlates with preferential transduction of these cells when vector is applied to the basolateral membrane relative to the apical membrane. However, binding studies of radiolabeled AAV-2 have shown only a four- to sevenfold reduction in binding to the cal membrane of WD HAE in culture as compared to the basal membrane. Because gene transfer efficiency was 200- fold greater following basal application than for luminal qiplication, the existence of apical membrane receptors for AAV-2 that are not functional for vector expression have been proposed (47,94). 

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