| Complex polar lipids are essential components of all living cell membranes. Phospholipids are the major structural lipids of all membranes, but they also have important functional properties as surfactants, as cofactors for membrane enzymes, as mediators of hypersensitivity, and as components of signal transduction systems. The primary route for de novo biosynthesis of phospholipids involves the activation of one of the components (either DAG or the head group) with CTP to form a high-energy intermediate, such as CDP-diglyceride or CDP-choline. In addition, there are exchange and modification reactions by which the animal cell interconverts various phospholipids. The other major types of membrane lipids are the sphingolipids, including sphingomyelin and various glycolipids. These lipids function as receptors for cell-cell recognition and interactions, and as binding sites for symbiotic and pathogenic bacteria and for viruses. Furthermore, various carbohydrate structures on the glycosphingolipids of red cell membranes are also the antigenic determinants responsible for the ABO and other blood types. Glycosphingolipids are degraded in the lysosomes by a complex sequence of reactions that involve a stepwise removal of sugars from the non-reducing end of the molecule, with each step involving a specific lysosomal exoglycosidase. A number of inherited lipid-storage diseases result from defects in degradation of glycosphingolipids.
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- Describe the role of plasmalogens vs. diacylglycerol-phospholipids in cell membrane structure and function.
- Discuss the challenges in development of a vaccine to protect against trypanosomiasis.
- Review current therapeutic approaches for treatment of acute respiratory distress syndrome (ARDS).
- In addition to the glycosphingolipidoses and mucopolysaccharidoses, what other lysosomal storage diseases might be treated by enzyme replacement therapy?
- Review the mechanisms of host-pathogen interaction, focusion on the role of lectins in microbial pathogenicity.
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| Brady RO. Enzyme replacement therapy: conception, chaos and culmination. Philos Trans R Soc Lond B Biol Sci 2003;358:915-919.
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| Dowhan W. Molecular basis for membrane phospholipid diversity: why are there so many lipids? Annu Rev Biochem 1997;66:199-232.
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| Garratty G, Telen MJ, Petz LD. Red cell antigens as functional molecules and obstacles to transfusion. Hematology (Am Soc Hematol Educ Program) 2002;445-462.
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| Hall C, Richards SJ, Hillmen P. The glycosylphosphatidylinositol anchor and paroxysmal nocturnal haemoglobinuria/aplasia model. Acta Haematol 2002;108:219-230.
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| Sandhoff K, Kolter T. Biosynthesis and degradation of mammalian glycosphingolipids. Philos Trans R Soc Lond B Biol Sci 2003;358:847-861.
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| Whitsett JA, Weaver TE. Hydrophobic surfactant proteins in lung function and disease. N Engl J Med 2002;347:2141-2148.
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