Polysaccharide inner structure

Figure 13-13. The glycogen molecule. A General structure. B Enlargement of structure at a branch point. The molecule is a sphere approximately 21 nm in diameter that can be visualized in electron micrographs. It has a molecular mass of 10 Da and consists of polysaccharide chains each containing about 13 glucose residues. The chains are either branched or unbranched and are arranged in 12 concentric layers (only four are shown in the figure). The branched chains (each has two branches) are found in the inner layers and the unbranched chains in the outer layer. (G, glycogenin, the primer molecule for glycogen synthesis.)...

L-glycero-mannoheptose. The polysaccharide component of LPS may be divided into several structural domains. The inner (core) domains vary relatively little between LPS molecules isolated from different Gram-negative bacteria. The outer (O-specific) domain is usually bacterial strain-specific. 

Principles to stabilize lipid bilayers by polymerization have been outlined schematically in Fig. 4a-d. Mother Nature — unfamiliar with the radically initiated polymerization of unsaturated compounds — uses other methods to-stabilize biomembranes. Polypeptides and polysaccharide derivatives act as a type of net which supports the biomembrane. Typical examples are spectrin, located at the inner surface of the erythrocyte membrane, clathrin, which is the major constituent of the coat structure in coated vesicles, and murein (peptidoglycan) a macromolecule coating the bacterial membrane as a component of the cell wall. Is it possible to mimic Nature and stabilize synthetic lipid bilayers by coating the liposome with a polymeric network without any covalent linkage between the vesicle and the polymer One can imagine different ways for the coating of liposomes with a polymer. This is illustrated below in Fig. 53. 

The basic structure of the mycobacterial cell wall is shown in O Fig. 1 (O Sect. 1). The major component of the cell wall is the mycolyl-arabinogalactan-peptidoglycan (mAGP) complex [21]. This consists of an inner peptidoglycan layer attached through a linker unit to an ara-binogalactan polysaccharide, which is in turn esterified to mycolic acids. The mycolic acids are branched hydroxy fatty acids that form the inner leaflet of the lipid bilayer. The outer leaflet... 

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