Protein lipidation patterns

Jackson, B. L. and Groves, J. T. (2007) Hybrid protein-lipid patterns from aluminum templates. Langmuir, 23, 2052-2057. 

By means of this method, a variety of Ras proteins with different lipidation patterns could be synthesized in multimilligram amounts. For instance, proteins were generated with the natural lipid combination, i.e. a farnesyl thioether and a palmitoyl thioester. Furthermore, analogous proteins were synthesized embodying only one lipid residue in which either the farnesyl- or the palmitoyl group was replaced by a stable hexadecyl thioether. In addition, proteins were built up containing a serine instead of a cysteine residue at the critical sites which normally are lipidated. In a further series of experiments, lipidated Ras proteins which carry a fluorescent Mant group incorporated into the farnesyl-type modification were synthesized.1251... 

Both marine and freshwater fish are often overfed in fish farms, so their own lipids are less likely to follow changes in the dietary lipid pattern. In the natural state, the influence of food on the lipids of the tissues is somewhat blurred by the fact that some of the tissue lipids are generated from carbohydrates and proteins in the diet and so synthesized de novo. In his classic work, Lovem (1964) showed that the impact of food on the fatty acid composition of herring lipids was most pronounced during intensive feeding. In winter, at the end of that period, the fatty acid composition became different from that of the zooplankton on which the fish had been feeding earlier. 

Complex II consists of four polypeptide subunits (70,000, 27,000, 13,500, and 7,000 daltons). The two larger subunits are components of succinate dehydrogenase and this enzyme or the entire complex II was directly incorporated into phospholipid vesicles at the high protein lipid ratio of 1 2 (w/w). The phospholipid (egg yolk lecithin) contained a small amount of lipid (d) (Table 6.2 I molecule in 1000) or lipid (e) (Table 6.2 1 in 400). After irradiation the labeling pattern was analyzed directly by SDS-polyacrylamide gel electrophoresis. Presumably the lipids that did not become attached to polypeptides ran at the dye front, although this was not demonstrated. 

Primary Results Morphology Population Distribution Chemical Patterns Elemental Composition Macromolecular Composition Lipid pattern Protein Pattern Small Key Metabolites Enzyme Activities Stress Markers... 

Fig. 29 A barcode of three different chemical functionalities formed in a silica capillary via spatially-selective polymerization. It consists of segments of poly(bis-SorbPC) doped with Rhodamine-capped DPPE (red), poly(bis-SorbPC) doped with NBD-capped DOPE (green), and DOPC doped with Ni2+-charged DOGS-NTA. After the lipid pattern was formed, 6xHis-tagged Cerulean, a blue fluorescent protein, was injected into the capillary and bound selectively to the immobilized Ni2+ (blue). The capillary inner diameter is 50 pm. Reprinted with permission from [96]. Copyright 2007, American Chemical Society...

Farokhzad et al. reported the immnnological characterization of lipid-polymer hybrid nanoparticles and proposed a method to control the levels of complement activation induced by these nanoparticles. In this method, the nanoparticle snrface was modified by attaching methoxyl, carboxyl, and amine groups. It was found that the snrface chemistry significantly affects human plasma and serum protein adsorption patterns. ... 

Fig. 4. Starch gel electrophoretic patterns and curve.s of radioactivity of labeled mixtures of Triton and a-LP. A a-LP-I i (2 mg), specific activity 0.5 pC/mg. B mixture of a-LP-PSt (2 mg) and Triton (40 mg) C Triton-I Si, specific activity 0.2 M-C/mg D mixture of a-LP (2 mg) and Triton-Ii i (40 mg). P = protein-stained pattern L = lipid-stained pattern (from Scanu and Oriente, 1961).

The response of serum lipid patterns in healthy young men to the ingestion of HEAR oil and LEAR oil was studied in a series of four metabolic studies in the Department of Foods and Nutrition at the University of Manitoba. The subjects, who were either students or employees of the University, resided In their own homes and maintained their usual activity patterns but ate all their meals in the Department. The experimental diets in these studies were designed so dietary fat could be carefully controlled and yet the diets consist of familiar foods (Bruce and McDonald, 1977). Fat supplied about 38-40% of the total energy in the diets, with the specific fat being studied supplying about 95% of this total. The diets consisted of customary foods but contained no meat. Textured soybean protein, egg albumen, and skim milk were the main protein sources. Soy protein was incorporated into en-... 

Fig. 1 C-terminal processing of CAAX box containing proteins and C-tenninal lipidation pattern of Ras (H-Ras, N-Ras, and K-Ras) and Rab proteins...

In the case of HDL, there are subtle changes of structure associated with changing lipid patterns as the particles evolve. Soluble HDL apolipo-proteins interact with well-defined synthetic phospholipids to form a disclike structure similar to that observed in vivo (section 5.3.5). In the absence of neutral lipids, the structural organization is dominated by the bilayer formation of the phospholipids. As neutral lipids (cholesterol esters and triacylglycerols) are incorporated into the core, the particles assume a spherical morphology that is governed by the hydrophobic interactions of the core lipids. 

Four different types of lipid-anchoring motifs have been found to date. These are amide-linked myristoyl anchors, thioester-linked fatty acyl anchors, thioether-linked prenyl anchors, and amide-linked glycosyl phosphatidylinosi-tol anchors. Each of these anchoring motifs is used by a variety of membrane proteins, but each nonetheless exhibits a characteristic pattern of structural requirements. 

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