Polysaccharide immobilization

A review on polysaccharide chemistry includes a section on water-insoluble polysaccharide immobilization of enzymes. 

Most studies on microbial exopolysaccharides production have been performed so far using batch fermentation conditions and polymer macromolecules are recovered from fermentation broths by simple chemical and physical techniques, e.g. precipitation and centrifugation. In Scheme 7.2 the route of production of alginate is presented [8]. Some attempts have been made to apply immobilized-cell cultures to the production of alginate and other bacterial polysaccharides. Immobilization techniques are likely to allow the permanent separation of microbial cells from the incubation broth. In the last few years, however, membrane processes have been increasingly used to separate microbial cells from the production medium. A number of studies have therefore focused on the microfiltration of fermentation broths after batch incubation and the mechanisms of membrane fouling by cells, debris, colloidal particles and macromolecules, e.g. for recovery of polysaccharides from fermentation broths [2]. 

Cellulose+ 2-amino-4,6-dichloro-s-triazine — Scheme 4.2 Polysaccharide immobilized enzymes [23]... 

Serra Moreno J, Sahhieti MG, Agas D, Marchetti L, Panero S. Polysaccharides immobilized in polypyrrole matrices are able to induce osteogenic differentiation in mouse mesenchymal stem cells. J Tissue Eng Regen Med 2012 8. 

Other immobilization methods are based on chemical and physical binding to soHd supports, eg, polysaccharides, polymers, glass, and other chemically and physically stable materials, which are usually modified with functional groups such as amine, carboxy, epoxy, phenyl, or alkane to enable covalent coupling to amino acid side chains on the enzyme surface. These supports may be macroporous, with pore diameters in the range 30—300 nm, to facihtate accommodation of enzyme within a support particle. Ionic and nonionic adsorption to macroporous supports is a gentle, simple, and often efficient method. Use of powdered enzyme, or enzyme precipitated on inert supports, may be adequate for use in nonaqueous media. Entrapment in polysaccharide/polymer gels is used for both cells and isolated enzymes. 

Table 6-1. Immobilization of enzymes and affinity ligands on polysaccharide matrices with CD1.

Shchipunov, Yu.A., Karpenko, T.Yu., Bakunina, I.Yu., Burtseva, Yu.V. and Zvyagintseva, T.N. (2004) A new precursor for the immobilization of enzymes inside sol-gel derived hybrid silica nanocomposites containing polysaccharides. Journal of Biochemical and Biophysical Methods, 58, 25-38. 

Chitosan (Fig. 16) is an amino-modified natural polysaccharide that canbe also used as a polymeric gel for the covalent binding of OND probes [61]. Chitosan offers several advantages for NA immobilization. Its pH responsive properties allow it to be easily immobilized onto glass slides for the construction of arrays. Specifically, chitosan is soluble at low pH, when its amine groups are protonated, but becomes insoluble when the pH is raised above its pKa 6.3). 

Interactions can also be studied at the surface of a coated capillary wall. One binding partner is first immobilized on the capillary wall. As a result of the affinity of the second binding partner, the analyte will be delayed, compared with migration times observed in an untreated capillary. Based on this approach, modified capillaries have been prepared and used successfully to study polysaccharide-protein interactions as well as affinity separations. Coating of the capillary wall with heparin and heparan sulfate has been used to determine the affinity of these polysaccharides for synthetic heparin-binding peptides different only in the stereochemistry of a single... 

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