Oligosaccharide lipids

Initiation includes synthesis of the oligosaccharide-lipid precursor and transfer of the oligosaccharide to a protein. Evidence for a possible role for retinol (vitamin A) as a carrier in this step is discussed in Chapter 38. 

Flowers, H.M., Batra, K.K., Kemp, J. Hassid, W.Z. (1968) Biosynthesis ot insoluble Glucans from Uridine Diphosphate-D-glucose with Enzyme Preparations from Phaseolus aureus and Lupinus albi, Plant Physiology, 43, 1703-9 Forsee, W.T., Griffin, J.A. Schutzbach, J.S. (1977) Mannosyltransfer fi om GDP-Mannose to Oligosaccharide Lipids , Biochemical and Biophysical Research Communications, 75, 799-805... 

Glycoprotein Biosynthesis I. Formation of an Oligosaccharide-lipid by Thyroid Slices and Evaluation of its Role in Protein Glycosylation , Journal of Biological Chemistry, 251, 6400-8... 

Bioreactors with immobilized enzymes or whole cells are utilized in a variety of areas. EMR have found widespread applications in the hydrolysis of macromolecules - proteins, poly- and oligosaccharides, lipids, etc. - for food and pharmaceutical applications (Prazeres and Cabral, 1994). More recently they have also begun to find application for the removal of various pollutants from wastewaters. An overview of the literature in these fields is described below. 

The attachment of D-glucose to a D-manno-oligosaccharide lipid intermediate from Nil 8 fibroblasts seems to serve an important role in the transfer of the oligosaccharide from the lipid carrier to the protein acceptor, since a related D-glucose-free oligosaccharide is transferred from its lipid intermediate to protein at a significantly reduced rate. ... 

Membrane preparations from lactating bovine mammary glands have been shown to incorporate o-mannose from GDP-o-mannose into lipid and into metabolically stable acceptors." It is postulated that the sequence GDP-o-mannose P -D-mannosyl-P -pyrophosphorylisoprenol P -o-mannosyl-oligosaccharide-P -pyrophosphoryl o-mannoprotein is followed. The structure of the oligosaccharide-lipid and the endogenous glycoproteins were not established. 

Possibly in support of the first hypothesis. Rosso et al. (1981) have shown that retinoid-deficient rats accumulate an oligosaccharide-lipid of the composition Man5(GlcNAc)2PPDol (reaction 2, Fig. 1), and that this shortened intermediate is rapidly replaced by the normal intermediate GlCjManglGlcNAcljPPDol upon treatment of the rats with retinyl acetate (reactions 3 and 4, Fig. 1). One interpretation of these data is that MRP might function in the synthesis of the oligosaccharide-lipid intermediate or that either retinoids or MRP, specifically, affect the activity of the MDP-dependent mannosyltransferase. In further support of this mechanism, De Luca et al. (1982) have demonstrated an accumulation of... 

Self-sorting is one of the most fundamental processes in living systems, which led complex mixtures of biomolecules (e.g., proteins, nucleic acids, oligosaccharides, lipids) to self-organize into larger biomacromolecular assemblies (e.g., DNA double-helix, multienzyme complexes, ribosomes) and finally into cellular compartments essential for the development of life on Earth. 

FiG. 12 Disaccharide lipids GLl, GLIB, and oligosaccharide lipids GL2, GL3 from Tsukamurella sp. 

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