Alginate molecules

Each calcium ion binds with two alginate molecules. The molecular weight of 195.16 relates to one alginate molecule, and the equivalent of half a calcium ion, therefore n = V2. 

Calcium alginate is incompatible with alkalis and alkali salts. Propranolol hydrochloride has been shown to bind to alginate molecules, suggesting that propranolol and calcium ions share common binding sites in the alginate chains the formation of the calcium alginate gel structure was impeded in the presence of propranolol molecules. ... 

O. Smidsrod and T. 1. Painter, Effect of periodate oxidation upon the stiffness of the alginate molecule in solution, Carbohydr. Res., 26 (1973) 125-132. 

Alginate lyase from Turbo cornutus acted on sodium alginate and resulted in a rapid decrease in viscosity and a gradual increase in reducing power of the substrate solution. The result of gel filtration of the reaction products indicated that uronic acid oligosaccharides were liberated as the final product. The fact that the enzyme attacked preferentially the D-mannuronate-rich moieties of the alginate molecule was demonstrated by an analysis with paper electrophoresis of the reaction products after acid treatment, which separated the uronic acid oligosaccharides from the uronic acid polysaccharides. 

This high viscosity observed at relatively low alginate concentration is due to the intramolecular electrostatic repulsion between the neighboring negative charges of each monomer unit that forces alginate molecules into an extended random coil conformation. ... 

Fig. 16. The eggbox model for the formation of junctions between alginate molecules. Calcium ions occupy the cavities formed by the opposing two-fold helical structures of the alginate molecules.

In a separate approach, hydrogel association of natural polymer (alginate) molecules could be performed in the presence of Ca +, for example, using liposomes as nanocontainers [10]. Alginate nanogels of 120-200 nm were obtained after removal of lipid bilayer by addition of surfactant. Nanogel size can be tuned by varying the nanocontainer volume and further controlled by the addition of monovalent salt to the dispersion. 

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