Carbohydrates divalent cations

Kohn R. (1987) Binding of divalent cations to oligomeric fragments of pectin. Carbohydr. Res. 160, 343-353. 

Minimal Interactions with Assay Components. If a buffer binds to or reacts with a component of the system, it should be avoided. For example, borate buffers can complex with alcohols and carbohydrates and great care should be exercised when utilizing these compounds. Some arsenate-based buffers have oxidizing potential with respect to thiols. Buffers should also have a low binding capacity with respect to divalent cations. 

Tang, J., Tling, M.A., and Zeng, Y. 1996. Compression strength and deformation of gellan gels formed with mono- and divalent cations. Carbohydrate Polymers 29 11-16. 

Selectins are a family of membrane glycoproteins that are divalent cation-dependent and bind to specific carbohydrates containing sialylated moieties. They are composed of leukocyte (L)-selectins, endothelial (E)-selectins and platelet (P)-selectins. L-selectins are expressed on most leukocytes, whereas vascular endothelial cells express E-selectins and P-selectins. Initial binding of leukocytes with vascular endothelium involves selectins and consequently they play an important role in leukocyte trafficking. 

Amino acids involved in binding M6P are shown in O Fig. 8. The phosphate moiety is coordinated by His 105, Asn 104, Asp 103 and divalent cation. Each hydroxyl of Man is hydrogen-bonded to binding site residues, while no interactions between the hydrophobic carbohydrate backbone and aromatic side chains are observed [148]. The multiple contacts between lectin and M6P, in contrast to that observed for many lectins which mediate cell surface interactions, are reflected in pM binding constants, reminiscent of bacterial arabinose-binding protein which functions as a sugar transport protein [149]. 

Persson A, Chang D, Crouch E. Surfactant protein D is a divalent cation-dependent carbohydrate-binding protein. J Biol Chem 1990 265 5755-60. 

The adsorption of several carbohydrate phosphates by bentonite was studied by Goring and Bartholomew (1951). The sequence of decreasing adsorption of the salts on monovalent cations was phytin > phytin derivatives > fructose 1-6 diphosphate > fruc-tose-6-phosphate > glucose-1-phosphate > glycerophosphoric acid > phosphoglyceric acid. Salts of divalent cations were adsorbed to a greater extent than those of monovalent cations. The carbohydrate phosphates were adsorbed to a much less extent by illite and kaolinite. 

Huang, Y. Gelling temperatures of high acyl gellan as affected by monovalent and divalent cations with dynamic rheological analysis. Carbohydr. Polym. 56 (2004) 27-33. 

Silva Filho EC, Lima LCB, Silva FC, Sousa KS, Fonseca MG, Santana SAA. Immobilization of ethylene sulfide in aminated cellulose for removal of the divalent cations. Carbohydr Polym 2013 92 1203-1210. 

Harvey, D. J. Ionization and collision-induced fragmentation of N-linked and related carbohydrates using divalent cations. Journal of the American Society for Mass Spectrometry 2001,12, 926-937. 

Many lectins depend on divalent metal cations, especially Ca, for carbohydrate binding. Two roles have been observed for metal cations. First, to preorganize side chains for saccharide binding, and second, to directly ligate saccharide hydroxyl... 

Transketolase (EC 2.2.1.1) an enzyme that catalyses transketolation, an important process of carbohydrate metabolism, especially in the Pentose phosphate cycle (see) and Calvin cycle (see). T. has been found in a wide variety of cells and tissues, including mammalian liver, green plants and many bacterial species. The enzyme contains divalent metal cations and the coenzyme, thiamin pyrophosphate. Transketolation involves transfer of a C2-unit (often called active glycolaldehyde or a ketol moiety) from a ketose to Cl of an aldose. Only ketoses with L-configuration at C3 and preferably irons configuration on the next carbon (i.e. Cl, 2, 3 and preferably 4 as in fructose) can serve as donors of the C2-unit. The acceptor is always an aldose. Thins-ketolation is reversible. Details of the reaction in which xylulose S-phosphate serves as the donor of... 

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