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A study was conducted on the synthesis, characterization and polymerization of a novel heterobifunctional lipid, 1-palmitoyl1-2-(2,4,12,14-tetraenehexadecanoyl)phosphatidylcholine. The results indicate that the polymerization was dependent on the mode of initiation, the polymerizable group and the position of the reactive group in the amphiphiles. Furthermore, the findings demonstrate the possibility of performing either selective or simultaneous polymerizations by appropriate choices of initiation chemistry.

A study was conducted on the effect of low proportions of single-chain lipids on phospholipase C-promoted fusion of large unilamellar vesicles with emphasis on the stalk model of membrane fusion. The findings indicate the involvement of inverted lipid structures in membrane fusion and that small amounts of hexadecane or squalene significantly increase the fusion rates. The results also support the stalk model of membrane fusion, particularly in its modified version.

Lipids with bulky hydrophilic polymer headgroups were observed to have large fluctuations normal to the monolayer plane, causing a systematic roughening of the interface and a decline in the coherently Bragg-scattering tail thickness with increasing polymer-lipid content. Findings indicated that bulky hydrophilic moieties result into substantial out-of-plan protrusions of phospholipid monolayers and presumably bilayers, vesicles and biological membranes.

Direct surface measurements of attractive reactions among uncharged lipid bilayers having lactosyl ceramide were implemented using a Mark II surface force device and with an SFA3 apparatus. A comparison of the measurement results with predicted theoretical values provided evidence for carbohydrate attraction between membranes exhibiting neutral glycosphingolipids. The results further suggested that the presence of the carbohydrate covering leads to higher nonspecific van der Waals forces between the membranes.

A study was conducted on the propensity for helix formation in the hydrophobic peptides K2(LA)x (x = 6, 8, 10, 12). The findings indicate that initial spreading pressure largely determines the secondary structure adopted by K2(LA)10 and K2(LA)12. The results also show the advantages of IR Reflection-Absorption Spectroscopy for the evaluation of peptide conformations in situ at the air/water interface as well as the significant differences in the propensity for helix formation in monolayers compared with bulk phases.

A study was conducted on the impact of the binding of annexin V on the structure and dynamics of phosphatidylcholine/phosphatidylserine bilayers. The findings indicate that binding of annexin V to planar supported bilayers has a significant influence on the lateral motion of both phosphatidylserine and phosphatidylserine molecules. Moreover, annexin V influences the lateral motion of lipids without inducing lateral phase separation.

Three oxidized lipid/amino acid reaction products (OLAARPs): 1-methyl-4-pentyl-1,4-dihydropyridene-3,5-dicarbaldehyde, 1-(5-amino-1-carboxypentyl)pyrrole and N-(carbobenzyloxy)-1(3)-microsomal system to study the role of the OLAARP formation in the oxidative process. Findings indicated that OLAARP formation may be an antioxidative defense mechanism by which oxidative stress is feed-back inhibited, delaying the damage due to reactive oxygen species.

Research was conducted to characterize the acylation defects in the YMN5 and TTA1 mutant strain in the lipid particles of the yeast Saccharomyces cerevisiae. Individual phospholipids were separated by two-dimensional thin-layer chromatography while lipid particles were obtained at high purity from cells growth to the late logarithmic phase. Results showed that yeast mitochondria do not harbor enzymes associated in the biosynthesis of phosphatidic acid.

Apolipoprotein B (apoB, protein; APOB, gene) is one of a dozen proteins associated with plasma lipoprotein particles and thus plays a crucial role in lipid metabolism. In recent years many [...], Two DNA polymorphisms, insertion/deletion (ins/del) and XbaI, of the apolipoprotein B (APOB) gene and their relationships with serum lipoprotein and lipid levels were examined in two Nigerian populations from Benin (n = 828) and Sokoto (n = 394). Allele frequencies for both polymorphisms were comparable between the two populations, and genotype frequencies conformed to Hardy-Weinberg equilibrium expectations. Because lipid profiles are affected by many known sex differences, males and females were analyzed separately. Analysis of variance was performed to test equality of means of quantitative traits across genotypes; the dependent variables were first adjusted by stepwise linear regression for environmental covariates in both populations. Plasma apoB and HDL2 cholesterol levels varied significantly between ins/del genotypes in Benin males (p = 0.05) and Sokoto males (p = 0.02), respectively. No significant variation between XbaI genotypes was observed for any lipid trait in either population. Combining the ins/del and XbaI polymorphisms to form haplotypes revealed significant linkage disequilibrium in both the Benin (p < 0.0001) and Sokoto (p < 0.001) populations. Analysis of the two-site haplotype showed a significant effect on serum lipoprotein (a) levels in Benin females (p < 0.04) and on HDL2 cholesterol among Sokoto males (p = 0.01). The haplotype explained 4% of the adjusted phenotypic variation in lipoprotein (a) levels in Benin females and 8.5% of the adjusted phenotypic variation in HDL2 cholesterol levels in Sokoto males. These data indicate that the ins/del and XbaI polymorphisms in the APOB gene affect interindividual variation in serum lipoprotein and lipid levels in African populations. KEY WORDS: APOLIPOPROTEIN B, AFRICAN BLACKS, CHOLESTEROL, ALLELLE FREQUENCY, INSERTION/DELETION, XbaI, LINKAGE DISEQUILIBRIUM

Several novel phosphoinositide 5-phosphatases have been identified and characterised, revealing a growing family of regulators of inositol lipid dependent processes. The features of these proteins, their likely partners and their involvement in signal transduction and membrane traffic is discussed.

The impact of the 90% reduction in galactolipid digalactosyldiacylglycerol (DGDG) in the dgd1 mutant of Arabidopsis thaliana on photosystem II was investigated. Results indicated that the kinetics of Q(sub A)(super *-) reoxidation by endogenous plastoquinone and the equilibrium constants between the states Q(sub A)(super -)Q(sub B) and Q(sub A)Q(sub B)(super *-) are very identical in the wild-type and the dgd1 mutant. Also, the dgd1 mutant has a small increase in the susceptibility to high-temperature stress.

Measurement of spontaneous transfer and transbilayer movement of BODIPY-labeled lipids in lipid vesicles was done through utilization of fluorescence intensity changes and nonlinear least-squares fitting program on C5-DMB-lipid analogs. Results have shown that the half-times for spontaneous interbilayer transfer of C5-DMB-lipids were longer than those obtained using C6-NBD-lipids. Both the head group and the backbone affect the rate of lipid flip-flop and spontaneous transfer.

The chemical structure of nontoxic diphosphoryl lipid A from Rhodobacter sphaeroides was confirmed using a combination of LSIMS (on a two-sector mass spectrometer) and MALDI (on time-of-flight and ion trap mass spectrometers) in conjunction with tandem mass spectrometry in both positive and negative ion modes. Accurate molecular weight measurement accompanied by the analysis of fragment ion masses yielded the composition of fatty acyl groups. Tandem experiments (collisionally induced dissociation of both quasimolecular and oxonium ions) were also performed, revealing the precise location and nature of the fatty acyl groups on the disaccharide backbone.

A method for the synthesis of cyclic borocane was developed based on the cyclic hydroboration of 2,6-dimethyl-1,6-heptadiene. The synthetic strategy involves the cross-coupling of Grignard reagents of methallyl chloride with 4-bromo-2-methyl-1-butene to produce 2,6-dimethyl-1,6-heptadiene. The synthetic sequence also involved the cyclic hydroboration/carbonylation, asymmetric enolization and ozonation of the derived enol silyl ether.

A study was conducted on the different lipid components of green Coffea arabica beans and their fatty acid composition. The analysis indicates the presence of fatty acids of C14, C16, C18 and C20 carbon chains in total oil, neutral lipids, polar lipids and pure triacylglycerols. The major fatty acids were palmitic and linoleic acids, which comprise about 38.7% and 35.9%, respectively. The hypercholesterolemic effects of coffee oil may be partly due to the presence of high amounts of palmitic acid at Sn-1,3 position.

The N-terminal 43 residues of human apolipoprotein A-I (apo hA-I) are necessary to maintain and stabilize the structure of these amino acids. They also play a crucial role in the conformational switch between the lipid-free and lipid-bound forms. Denaturant-induced unfolding, binding of the fluorescent probe 1-anilinonaphthalene-8-sulfonate, surface balance measurements and far- and near-ultraviolet circular dichroic spectroscopy showed significant structural differences between lipid-free apo (delta)(1-43)A-I and apo hA-I. According to spectral and physical measurements, apo (delta)(1-43)A-I has a folded, tertiary structure, although it is substantially less stable than that of apo hA-I.

The structure of mitogenic lipids from Bacillus subtilis was analyzed to determine the mechanisms that mediate the mitogenic activity of bacterialglycerophosphoglycolipids. The lipid structure was elucidated as 1,2-diacyl-3-omicron-[6-(sn-glycero-1-phospho)-beta-D-glucopyranosyl- (1-6)-beta-D-[glucopyranosyl]glycerol. The microbial mitogenic lipid also exhibited a mitogenically active but less potent glycolipid with esterified fatty acids in the head group.

Cholesterol preserved in archaeological bones and teeth constitutes an important new source of palaeodietary information. A method is described here for the isotopic ([[Delta].sup.13]C) determination of cholesterol employing a semi-automated sample preparation procedure and the technique of isotope ratio monitoring/gas chromatography/ mass spectrometry (irm/GC/MS). High-temperature gas chromatography (HT-GC) and high-temperature gas chromatography/mass spectrometry (HT-GC/MS) were used to identify the lipids and quantify the cholesterol present in the total lipid extracts. ([[Delta].sup.13]C) values are then readily obtained from nanogram amounts ([approximately]50 ng) of cholesterol resolved and determined directly by high-resolution capillary irm/GC/MS of trimethylsilylated total lipid extracts. The protocol developed allows effective processing of the large numbers of samples essential for palaeodietary determinations. Analytical precision and reproducibility have been assessed through multiple sampling of the same skeleton (femur, 9th century). Comparable ([[Delta].sup.13]C) values have been obtained from different skeletal members from the same individual. The utility of the approach is demonstrated through a study of the ([[Delta].sup.13]C) values of cholesterol isolated from sections of femoral bones of individuals excavated from cemeteries (dated Saxon to 18th century) at a coastal site in the U.K. The mean ([[Delta].sup.13]C) value (-22.2 [+ or -] 0.3[per thousand], [Sigma] = 0.9) determined for cholesterol in 50 different individuals indicates a strong preference for marine foods by the members of the community extending back over the last [approximately] 1500 years. A minority of individuals exhibited ([[Delta].sup.13]C) values as low as -26[per thousand], indicating preferences for terrestrial rather than marine foodstuffs.

A simple preparation of a DNA-lipid complex which is soluble in organic media but is insoluble in aqueous solutions and a simple formation of a DNA-aligned, self-standing, water-insoluble film are described. The DNA-lipid complex can be prepared by replacing sodium counter cations by cationic amphiphilic lipids. The complex forms double helical strands even in organic media. By changing the water content, the internal conformation of DNA strands can be reversibly altered from B-form to C-form in the organic solution.

High concentrations of hydrocarbons and long-chain C20 to C32 n-alkenes were detected in the lipids of Mytilus edulis that are located along the water columns of Sable Island, Nova Scotia. The mussels that were located within one kilometer of the oil drilling sites have varied hydrocarbon content with minimal concentrations of branched aliphatic hydrocarbons. The n-alkenes was absorbed by Mytilus edulis from the oil base mud that was utilized in drilling operations. The concentrations of n-alkenes in the mussels depends on the location and environmental abundance of the compounds.

Addition of ascorbate 2-monophosphate and ascorbate 2-polyphosphate is most effective in inhibiting lipid oxidation, and maintaining the meaty flavor and aroma of ground meat. Ascorbic acid addition fails to inhibit oxidative changes in turkey, whereas sodium ascorbate reduces oxidation in beef. Phosphate salts fail to influence the fat content of the meat, but decrease the loss in cooking. They also lead to a decrease in the nonheme iron in patties made of turkey, but fail to do so in beef patties.

Addition of propyl gallate, alfa-tocopherol, or tripolyphosphate antioxidants in the washing process inhibits protein and lipid oxidation in beef heart surimi. Ascorbate fails to prevent protein oxidation, and increases protein carbonyls which are correlated with the gelation property of gels. Oxidation inhibition fails to affect surimi gelation. The storage of sol increases protein oxidation in ascorbate-washed surimi pellets. Incorporation of tripolyphosphate increases protein gelation, irrespective of the oxidization status of the surimi.

The synthesis and characterization of ATP-lipids where the nucleotides are covalently attached to the the C8- or N6-position of the adenine ring to the lipid are described. The ATP-lipids were characterized by different enzyme assays in micellar solution. The results indicate that these novel ATP-lipids can be used to form phantom cells, actin-supported membranes or to orient and crystallize ATP-binding proteins at lipid interfaces.

Three pulmonary surfactant proteins, (SP)-A, SP-B, and SP-C, are involved in the regulation of lipid uptake by pulmonary epithelial cells in vitro. The incorporation of SP-C in lipid vesicles of rat type II epithelial cells increases binding to the cell membrane at 4 degrees celsius and endocytosis of lipids at 37 degrees celsius. SP-B increases lipid uptake in MLE-12 cells but simultaneously decreases lipid uptake by SP-C. SP-A has no effect on the endocytosis of lipids by MLE-12 cells or type II cells, but helps in lipid aggregation within the cell surface.

Raw ground patties of chicken meat have a lower oxidation potential than beef or pork patties when stored at -20 degrees celsius (C). However, cooked chicken patties at 4 degrees C have a higher oxidation potential than beef or pork patties. The values of heme iron and 2-thiobarbituric acid (TBA) are higher in raw frozen beef and pork than chicken. TBA values for cooked patties were highest for chicken, which also contain the highest amount of polyunsaturated fatty acids at all storage temperatures. The TBA values indicate the oxidation potential of the meat.

Three cationinic amphiphilic imidazolinium compounds have been developed which will be pivotal for in vitro and in vivo gene delivery. These compounds are found to differ only in the structure of the hydrophobic acyl chains, but they vary greatly in their ability to mediate in vivo and in vitro gene delivery. During in vitro gene delivery, the myristoyl form is most effective, while the most effective compound in vivo is the oleoyl form. On suspension in aqueous media, these lipids form liposomes and when treated with plasmid DNA, the lipid particles coalesce to form larger particles.

Spectroscopic and lipid binding studies on the amino and carboxyl terminal fragments of Locusta migratoria apolipophorin III (apoLp-III) show that, besides amphipathic alpha-helices, structural elements of the intact protein helps in the lipid binding abilities of apoLp-III. The isolated amino and carboxyl terminal fragments of the protein cannot imitate the functional capacity of the intact protein, though it can enable interactions with lipids. Ionic and hydrophobic interactions have been suggested to play a main role in the initiation of binding events.

Chloroplast lipoxygenase is necessary for wound-initiated jasmonic acid (JA) aggregation in Arabidopsis leaves indicating that the protein is targeted to chloroplasts. The expression of a wound-and and JA-inducible Arabidopsis gene was determined in transgenic and control plants using a transgenic approach. Wound induced JA is required for wound induced regulation of Arabidopsis gene. The amino acid sequence and expression pattern of LOX2 is different from other known Arabidopsis LOX gene indicating that the related enzymes have different roles within plants.

The degree of polyunsaturation in fatty acids and in dietary tocopherols controls the amount of tocopherols in the tissues and the storage stability of the meat. The composition of the muscle fatty acids is affected by the addition of a mixture of alfa-linoleic acid and tocopherols to the diet of broiler chicken. A mixture of linoleic acid and tocopherols increases the degree of unsaturation in neutral lipids and phospholipids. The lipid oxidation in the loosely packaged cooked meat is not affected by the dietary tocopherols.

A study of the influence of intraluminal lipid infusion on gastrointestinal electrical activity in chickens shows that intraluminal lipid infusion reduces the frequency of gastric cycle, enhances duodenogastric refluxes and elongates the migrating myoglobin complex. An ileal brake mechanism similar to that present in mammals occurs in chickens. The experimental procedure of the study is discussed.

The transverse distribution of a pyrene moiety which binds to the terminal methylene unit of a phospholipid acyl chain is identified by the length and conformation of the linked chain, which increased the usefulness of the pyrenyl phospholipids for the localization of other fluorophores by using the resonance energy transfer technique. The pyrene moiety showed no intrinsic tendency on the bilayer surface which causes it to force the acyl chains into a distorted conformation.

Land snails, Otala lactea, were studied to determine the function of elevated antioxidant enzymes during dormancy. Dormant and active snails were compared. After 30 days of dormancy, antioxidant enzymes had increased in the foot muscle and the hepatopancreas. Results indicate the enzyme increase serves as a defense mechanism, to protect the snail from oxidative stress when aroused.

Two lipids from the bacterium Deinococcus radiodurans, 1,2-diacyl-3-alpha-glucopyranosyl-glycerol and 3-O-(6'-O-1',2'-diacyl-3'-phosphoglycerol-alpha-glucopyranosyl)-1,2-diacyl glycerol are different from other polar lipids previously characterized from D. radiodurans. The two lipids are novel in that they exist in other bacteria than genus Deinococcus bacteria and have homologues in both gram-negative and gram-positive bacteria. The structure of these new lipids are characterized.

Similarities between the structure of chitolipooligosaccharides and membrane lipopolysaccharides of Rhizobium indicate that chitolipooligosaccharides are probably synthesized in the bacterial membrane. The extent to which chitolipooligosaccharides are sulfated or methylated is usually reflected in the other membrane lipids. The position and extent of fatty acid saturation is also similar. Chitolipooligosaccharides are signal molecules that regulate the response of the host plant to the bacterium.

Mass spectrometric, nuclear magnetic spectroscopic and compositional analysis of the chemical structure of lipid A obtained from Porphyromonas gingivalis shows that the backbone of the lipid that contains beta(1,6)-linked D-glucosamine disaccharide 1-phosphate and phosphate at position 1 and 4 will affect its activity. The amino acid groups present at 2 and 2' positions are acylated by (R)-3-OH-iC(sub 17:0) and (R)-3-O-C(sub 16:0)-iC(sub 17:0). The esterification of positions 3 and 3' is mediated by (R)-3-OH-C(sub 16:0) and (R)-3-OH-iC(sub 15:0).

Regression analyses of several men aged below 60 years helps understand the correlation between psychosocial variables such as anger and Type A behavior, and plasma lipids. The variations in the values of glycerides and high- and low-density lipoproteins are explained by anger-out, controlled anger, anger held-in and Type A behavior.

A one-year study of lipid and glycogen levels in newly recruited Abarenicola pacifica indicated that they were independent of seasonality or growth rates. The glycogen content increased gradually, while lipid levels decreased. Storage lipids, particularly triacylglycerides, quantitatively increased during oogenesis.

Two N-nitrilotriacetic acid (NTA) lipids, a phospholipid and NTA-DODA(dioctadecylamine) are synthesized. NMR, TLC and FTIR experiments help characterize the products and film balance techniques confirm the formation of metal sensitive lipid films. Presence of Ni(2+) leads to significant changes in the electrical and physical properties of the lipid head group. Use of the NTA-chelator is an efficient method in molecular biology and protein engineering for analysis of oligo-histidine-tagged fusion proteins and self-assembling systems.

A comparison of complex polar lipids in a hot spring cyanobacterial mat cultivated from various habitats helps examine microbial sources of major mat lipids. Fast atom bombardment mass spectrometry helps examine the masses in complex polar lipid components. Two-dimensional thin layer chromatography helps determine the chemistry of complex polar lipid components. Major lipids of mats are similar to those of cyanobacterial isolates.

Cell hydrophobicity depends on rhamnolipid biosurfactant concentration and octadecane biodegradation controlled by surface properties of the degrading cells and the aqueous dispersion of octadecane. Biodegradation by fast degraders is reduced and that by slow degraders is increased at high rhamnolipid levels.