Alginate: properties and biomedical applications

Advances in determination of polymer structure and in preservation of structure for electron microscopy provide the best view to date of how polysaccharides and structural proteins are organized into plant cell walls. The walls that form and partition dividing cells are modified chemically and structurally from the walls expanding to provide a cell with its functional form. In grasses, the chemical structure of the wall differs from that of all other flowering plant species that have been examined. Nevertheless, both types of wall must conform to the same physical laws. Cell expansion occurs via strictly regulated reorientation of each of the wall's components that first permits the wall to stretch in specific directions and then lock into final shape. This review integrates information on the chemical structure of individual polymers with data obtained from new techniques used to probe the arrangement of the polymers within the walls of individual cells. We provide structural models of two distinct types of walls in flowering plants consistent with the physical properties of the wall and its components.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-313X.1993.tb00007.x

Structural models of primary cell walls in flowering plants: consistency of molecular structure with the physical properties of the walls during growth

https://febs.onlinelibrary.wiley.com/doi/epdf/10.1016/0014-5793%2873%2980770-7

Biological interactions between polysaccharides and divalent cations: The egg‐box model

Recently, we found that ZO-1, a tight junction-associated protein, was concentrated in the so called isolated adherens junction fraction from the liver (Itoh, M., A. Nagafuchi, S. Yonemura, T. Kitani-Yasuda, Sa. Tsukita, and Sh. Tsukita. 1993. J. Cell Biol. 121:491-502). Using this fraction derived from chick liver as an antigen, we obtained three monoclonal antibodies specific for a approximately 65-kD protein in rats. This antigen was not extractable from plasma membranes without detergent, suggesting that it is an integral membrane protein. Immunofluorescence and immunoelectron microscopy with these mAbs showed that this approximately 65-kD membrane protein was exclusively localized at tight junctions of both epithelial and endothelial cells: at the electron microscopic level, the labels were detected directly over the points of membrane contact in tight junctions. To further clarify the nature and structure of this membrane protein, we cloned and sequenced its cDNA. We found that the cDNA encoded a 504-amino acid polypeptide with 55.9 kDa. A search of the data base identified no proteins with significant homology to this membrane protein. A most striking feature of its primary structure was revealed by a hydrophilicity plot: four putative membrane-spanning segments were included in the NH2-terminal half. This hydrophilicity plot was very similar to that of connexin, an integral membrane protein in gap junctions. These findings revealed that an integral membrane protein localizing at tight junctions is now identified, which we designated as "occludin."

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Occludin: a novel integral membrane protein localizing at tight junctions.

INTRODUCTION 487 MORPHOLOGY AND OBSERVATION OF FOCAL ADHESIONS 488 FORMATION OF FOCAL ADHESIONS 490 DYNAMICS OF FOCAL ADHESION COMPONENTS ...... 491

/pdf/focal-adhesions-transmembrane-junctions-between-the-2fze6e5w5x.pdf

Focal adhesions: Transmembrane junctions between the extracellular matrix and the cytoskeleton

Concentration and shear rate dependence of viscosity in random coil polysaccharide solutions

The agarose double helix and its function in agarose gel structure

Conformations and interactions of pectins. I. Polymorphism between gel and solid states of calcium polygalacturonate

Associations of like and unlike polysaccharides: Mechanism and specificity in galactomannans, interacting bacterial polysaccharides, and related systems

David A. Rees

Papers

Biological interactions between polysaccharides and divalent cations: The egg‐box model

Concentration and shear rate dependence of viscosity in random coil polysaccharide solutions

The agarose double helix and its function in agarose gel structure

Conformations and interactions of pectins. I. Polymorphism between gel and solid states of calcium polygalacturonate

Associations of like and unlike polysaccharides: Mechanism and specificity in galactomannans, interacting bacterial polysaccharides, and related systems