Lipids terms Links

Superose gel material of Pharmacia Biotech is a highly epichloro-hydrine cross-linked agarose matrix that has a pH range of 3-12 (short term 1-14). Hydrophilic interactions may be noticeable for lipids, peptides, and small aromatic compounds, but such interactions might even improve resolution. Superose medium is available in two different porosities Superose 6 HR 10/ 30 (bead size 13 2 /um maximum pressure 1.5 MPa) and Superose 12 HR 10/30 (bead size 10 2 /um maximum pressure 3.0 MPa). 

A lipopolysaccharide (LPS) is any compound consisting of covalently linked lipids and polysaccharides. The term is used more frequently to denote a cell wall component from Gram-negative bacteria. LPS has endotoxin activities and is a polyclonal stimulator of B-lymphocytes. 

The effect of alum as adjuvant was also tested in the liposphere-vaccine formulation. In the presence of lipid A, enhanced immune response is obtained even in the absence of alum. This observation is very important because there is increasing concern about the toxic side effects of alum in the long term. Research has suggested a link between aluminum and diseases of the brain, including Alzheimer s disease. 

The structural components encountered in E. coli are also present in lipid A of other bacterial sources. Thus, a survey of the structures analyzed shows that lipid A, in general, contain two g/wcoconfigured and pyranosidic D-hexosamine residues (2-amino-2-deoxy-D-glucose, GlcpN, or 2,3-diamino-2,3-dideoxy-D-glucose, GlcpN3N, also termed DAG (49,50)], which are present as a ) -(l — 6)-linked disaccharide (monosaccharide backbones have also been identified, but the respective lipid A lack endotoxic activity). The disaccharide is phosphorylated by one or, in most cases, two phosphate... 

Neutrophil membranes contain inositol lipids, which comprise about 5-6% of the total membrane lipids. About 80% of these inositol lipids possess stearic acid (Cl8 0) at Cl and arachidonic acid (C20 4) at C2 positions. Phosphatidylinositol accounts for most of these lipids (90%), with smaller amounts of PIP (6%) and PIP 2 (4%), which are synthesised sequentially by the action of 4- and 5-specific kinases, respectively (see Fig. 6.6). Neutrophil membranes also possess a phosphatidylinositol-specific phospholipase C which cleaves phosphatidylinositol 4,5-bisphosphate (PIP2) into Ins 1,4,5 P3 and DAG (Fig. 6.7). Both PLC-/3(/ 2) and PLC-y (72) families appear to be present in neutrophils. The coupling of receptor occupancy to PLC activation in neutrophils can be through a heterotrimeric G-protein, the mobile subunit of which has been termed G p. Evidence for this G-protein link comes from the following facts ... 

Polymers having carbohydrate chains linked to a lipid anchor embedded in a bacterial membrane the term bacterial amphiphiles was suggested5 for these polymers. Lipopolysaccharides of Gram-negative bacteria constitute the best-known example of these polymers. 

Figure 1 represents the general structure of Salmonella lipopolysaccharides. They contain an external polysaccharide, the O-antigenic chain, and an innermost component, termed lipid A. O-chain and lipid A are linked to each other by an oligosaccharide referred to as the core. O-Specific Chains. As indicated in Figure 1, O chains are in general made up of repeating units of di-, tri-, or higher oligosaccharides. In rare cases the O-chain is a homopolysaccharide. The structure of the O-chain is unique to each bacterial serotype great diversity is encountered in the structures of O-chains.

Hair is composed of approximately 65 to 95% protein, 1 to 9% lipid, and small quantities of trace elements, polysaccharides, and water. - - The majority of hair protein is often referred to as keratin, which is a general term used to describe aggregates of protein with low or high sulfur content. These proteins are synthesized in the keratogenous zone of the hair follicle as matrix cells move upward from the hair bulb to form layers of the hair shaft. The cuticle, cortex, and medulla are comprised largely of keratin, although it is structurally different in each layer. Keratin in the exocuticle contains a high concentration of cysteine, which forms disulfide bonds which link the A-layer to the exocuticle, and this makes the cuticle... 

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