bluuebunny/crossref_metadata_2025_split huggingface dataset:
Protein engineering and applications of Candida rugosa lipase isoforms
Authors: Akoh Casimir C. , Lee Guan‐Chiun , Shaw Jei‐Fu 
Published: November 2006

AbstractCommercial preparations of Candida rugosa lipase (CRL) are mixtures of lipase isoforms used for the hydrolysis and synthesis of various esters. The presence of variable isoforms and the amount of lipolytic protein in the crude lipase preparations lead to a lack of reproducibility of biocatalytic reactions. Purification of crude CRL improve their substrate specificity, enantioselectivity, stability, and specific activities. The expression of the isoforms is governed by culture or fermentation conditions. Unfortunately, the nonsporogenic yeast C. rugosa does not utilize the universal codon CTG for leucine; therefore, most of the CTG codons were converted to universal serine triplets by site‐directed mutagenesis to gain expression of functional lipase in heterologous hosts. Recombinant expressions by multiple‐site mutagenesis or complete synthesis of the lipase gene are other possible ways of obtaining pure and different CRL isoforms, in addition to culture engineering. Protein engineering of purified CRL isoforms allows the tailoring of enzyme function. This involves computer modeling based on available 3‐D structures of lipase isoforms. Lid swapping and DNA shuffling techniques can be used to improve the enantioselectivity, thermostability, and substrate specificity of CRL isoforms and increase their biotechnological applications. Lid swapping can result in chimera proteins with new functions. The sequence of the lid can affect the activity and specificity of recombinant CRL isoforms. Candida rugosa lipase is toxicologically safe for food applications. Protein engineering through lid swapping and rationally designed site‐directed mutagenesis will continue to lead to the production of CRL isoforms with improved catalytic power, thermostability, enantioselectivity, and substrate specificity, while providing evidence for the mechanisms of actions of the various isoforms.
Effects of specific conjugated linoleic acid isomers on growth characteristics in obese Zucker rats
Authors: Sanders Sara R. , Teachey Mary K. , Ptock Arne , Kraemer Klaus , Hasselwander Oliver , Henriksen Erik J. , Baumgard Lance H. 
Published: November 2006

AbstractGrowing female obese Zucker (fa/fa) rats were treated (via intragastric gavage) for 21 d with either a (i) vehicle [corn oil; 0.9 g/kg body weight (BW)], (ii) CLA mixture [50∶50; trans‐10,cis‐12 and cis‐9,trans‐11 CLA], (iii) cis‐9,trans‐11 CLA, or (iv) trans‐10,cis‐12 CLA (CLA treatments at 1.5 g CLA/kg BW). Compared with controls, average daily gain (g/d) was reduced 24 and 44% by the CLA mixture and trans‐10,cis‐12 CLA, respectively There was no treatment effect on average whole‐body (minus heart and liver) composition (dry matter basis): fat (70.2%), protein (21.0%), and ash (4.3%). Compared with animals treated with cis‐9,trans‐11 CLA, obese Zucker rats treated with trans‐10,cis‐12 and the CLA mixture had 7.8% more carcass water. Treatment had no effect on heart or liver weights or on heart or liver weights as a percentage of body weight, but compared with the other treatments trans‐10,cis‐12 CLA increased liver lipid contentby 33%. Hepatic lipid ratios of 16∶1/16∶0 and 18∶1/18∶0 (a proxy for Δ9‐desaturase capability) were not affected by treatment (0.1 and 0.6, respectively). Simlar to previous reports, CLA increased hepatic lipid content and altered both liver and carcass FA composition (i.e., reduced arachidonic acid content), but the ability of CLA to manipulate body composition in obese Zucker rats remains questionable.
Phospholipase D and phosphatidate phosphohydrolase activities in rat cerebellum during aging
Authors: Pasquaré S. J. , Salvador G. A. , Giusto N. M. 
Published: November 2006

AbstractAging is a process that affects different organs, of which the brain is particularly susceptible. PA and DAG are central intermediates in the phosphoglyceride as well as in the neutral lipid biosynthetic pathway, and they have also been implicated in signal transduction. Phospholipase D (PLD) and phosphatidate phosphohydrolase (PAP) are the enzymes that generate PA and DAG. The latter can be transformed into MAG by diacylglycerol lipase (DGL). In the present study, we examine how aging modulates the PLD, PAP, and DGL isoforms in cerebellar subcellular fractions from 4‐(adult),28‐, and 33‐mon‐old (aged) rats. Pl‐4,5‐bisphosphonate (PIP2)‐dependent PLD, PAP1, and DGL1 were distributed in different percentages in all cerebellum subcellular fractions. On the other hand, PAP2 and DGL2 activities were observed in all subcellular fractions except in the cytosolic fraction. Aging modified the enzyme distribution pattern. In addition, aging decreased nuclear (45%), mitochondrial‐synaptosomal (55%), and cytosolic (71%) PAP1 activity and increased (28%) microsomal PAP1 activity. DGL1 activity was decreased in nuclear (85%) and mitochondrial‐synaptosomal (63%) fractions by aging. On the other hand, PIP2‐dependent PLD activities were increased in the mitochondrial‐synaptosomal fraction. PAP2 and DGL2 were increased in the microsomal fraction by 87 and 114%, respectively, and they were decreased in the nuclear fraction. The changes observed in cerebellum PAP1 and DGL1 activities from aged rats with respect to adult rats could be related to modifications in lipid metabolism. Differential PA metabolization during aging through PIP2‐dependent PLD/PAP2/DGL2 activities could be related to alterations in the neural signal transduction mechanisms.
Isolation and structures of two divinyl ether fatty acids from Clematis vitalba
Authors: Hamberg Mats 
Published: November 2006

Abstract[1‐14C]Linolenic acid was incubated with a homogenate of leaves of Clematis vitalba, a plant belonging to the Ranunculaceae family. Analysis of the reaction product by reversed‐phase high‐performance liquid radiochromatography demonstrated the presence of the following labeled oxylipins: 12‐oxo‐10,15(Z)‐phytodienoic acid, 9(S‐hydroxy‐10(E),12(Z),15(Z)‐octadecatrienoic acid, ω5(Z)‐etherolenic acid, and 9‐[1′(E),3′(Z),6′(Z)‐nonatrienyloxy]‐8(Z)‐nonenoic acid [8(Z)‐colnelenic acid]. The last compound was a new divinyl ether FA, and an analogous compound, i.e., 9‐[1′(E),3′(Z)‐nonadienyloxy]‐8(Z)‐nonenoic acid [8(Z‐colneleic acid], was obtained following incubation of linoleic acid with the Clematis homogenate. Structures of the two divinyl ethers were assigned by spectral and chromatographic comparison with authentic compounds prepared synthetically using previously described methodology. Separate incubation of the 9‐ and 13‐hydroperoxides of linolenic acid demonstrated that the first hydroperoxide served as the precursor of 8(Z)‐colnelenic acid and indicated the presence in C. vitalba of a new divinyl ether synthase acting on 9‐lipoxygenase‐generated hydroperoxides. A close structural relationship between this enzyme and the well‐studied divinyl ether synthase in the potato and tomato seems likely.
Geranium sanguineum (Geraniaceae) seed oil: A new source of petroselinic and vernolic acid
Authors: Tsevegsuren N. , Aitzetmuller K. , Vosmann K. 
Published: November 2006

AbstractThe occurrent of petroselinic acid (18∶1Δ6cis) in seed oils was believed to be limited to the Umbelliferae or Apiaceae, and a few other members of the Umbelliflorae. A major occurrence of petroselinic acid outside the Umbelliflorae must therefore be regarded as highly unusual and surprising. The seed oil of Geranium sanguineum, a member of the family Geraniaceae, has now been found to contain petroselinic and vernolic acids as major FA in its seed oil TAG. These unusual FA have not been reported previously as constituents of Geraniaceae seed oils. The structure and composition of the seed oil FA from G. sanguineum were determined by combined use of chromatographic (TLC, capillary GLC) and spectroscopic (IR, GC‐MS) techniques. The double‐bond position in petroselinic acid was located unambiguously by the characteristic mass fragmentation of its dimethyldisulfide (DMDS) adduct. The epoxy FA was identified as vernolic acid by co‐chromatography and by the mass fragments formed during GC‐MS of the products of the epoxy ring‐opening reaction with BF3 in methanol.
Reaction of mono‐epoxidized conjugated linoleic acid ester with boron trifluoride etherate complex
Authors: Jie Marcel S. F. Lie Ken , Lam Corey N. W. 
Published: November 2006

AbstractThe reaction of methyl 11, 12‐E‐epoxy‐9Z‐octadecenoate (1) with boron trifluoride etherate furnished a mixture of methyl 12‐oxo‐10E‐octadecenoate (3a) and methyl 11‐oxo‐9E‐octadecenoate (3b) in 66% yield. Methyl 9, 10‐Z‐epoxy‐11 E‐octadecenoate (2) with boron trifluoride etherate furnished a mixture of methyl 9‐oxo‐10 E‐octadecenoate (4a, 45%) and methyl 10‐oxo‐11 E‐octadecenoate (4b, 19%). A plausible mechanism is proposed for these reactions, which involves the attack on the epoxy ring system by BF3, followed by deprotonation, oxo formation, and double bond migration to give a mixture of two positional α,β‐unsaturated C18 enone ester derivatives (3a/3b, 4a/4b). The structures of these C18 enone ester derivatives (3a/3b, 4a/4b) were identified by a combination of NMR spectroscopic and mass spectrometric analyses.
Successful utilization of lyophilized lipoprotein(a) as a biological reagent
Authors: Scanu Angelo M. , Hinman Janet , Pfaffinger Ditta , Edelstein Celina 
Published: November 2006

AbstractLipoprotein(a) [Lp(a)] represents a class of lipoprotein particles having as a protein moiety apoB‐100 linked by a single disulfide bond to apolipoprotein(a) [apo(a)], a multikringle structure with a high degree of homology with plasminogen. A recognized feature of Lp(a) is its instability on storage caused by attendant protein and lipid modifications that affect the structural, functional, and immunological properties of this lipoprotein. Here we present data showing that, under appropriate conditions of cryopreservation, Lp(a) retains the properties of the freshly isolated product, and we provide examples supporting the stability of this cryopreserved product as a primary standard in immunoassay settings and in cell culture systems.
A short, concise route to diphosphatidylglycerol (Cardiolipin) and its variants
Authors: Krishna U. Murali , Ahmad Moghis U. , Ali Shoukath M. , Ahmad Imran 
Published: November 2006

AbstractA new approach is described for the synthesis of the cardiolipin family of phospholipids that uses phosphonium salt methodology. The method involves the reaction of 2‐O‐protected glycerol with a trialkyl phosphite derived from 1,2‐diacyl‐sn‐glycerol in the presence of pyridinium bromide perbromide and triethylamine to afford the phosphoric triesters. The synthesis involves three steps and allows the preparation of a wide range of cardiolipins with different substitution patterns and chain lengths, including unsaturated derivatives. The use of inexpensive protecting groups and the ease of purification facilitate this synthetic route and allow its scale‐up in a higher overall yield (72%) than the literature methods.
The age‐related decline in intestinal lipid uptake is associated with a reduced abundance of fatty acid‐binding protein
Authors: Woudstra Trudy D. , Drozdowski Laurie A. , Wild Gary E. , Clandinin M. T. , Agellon Luis B. , Thomson Alan B. R. 
Published: November 2006

AbstractAging is associated with changes in the absorptive capacity of the small intestine. We tested the hypotheses that (i) aging is associated with a decline in lipid absorption, and that (ii) this decreased lipid absorption is due to a decline in the abundance of mRNA and/or the enterocyte cytosolic intestinal FA‐binding protein (I‐FABP), the liver FA‐binding protein (L‐FABP), and the ileal lipid‐binding protein (ILBP). In vitro uptake studies were performed on Fischer 344 rats at ages 1, 9, and 24 mon. Northern blotting (L‐FABP, ILBP) and immunohistochemistry (I‐FABP, ILBP) were performed. Aging was associated with decreased animal weights, but the surface area of the intestine was not significantly altered with age. The rates of ileal uptake of 16∶0, 18∶0, 18∶1, and 18∶2 were reduced by greater than 50% with aging when expressed on the basis of mucosal weight. This decline was not associated with reduced expression of mRNA for L‐FABP or ILBP but was associated with a 50% decrease in the abundance of I‐FABP and a 40% decrease in the abundance of ILBP. Thus, the decrease with aging in the ileal uptake of some FA when rates were expressed on the basis of mucosal weight was associated with a reduced abundance of I‐FABP and ILBP.
Conjugated linoleic acid isomer effects in atherosclerosis: Growth and regression of lesions
Authors: Kritchevsky David , Tepper Shirley A. , Wright Scott , Czarnecki Susanne K. , Wilson Thomas A. , Nicolosi Robert J. 
Published: November 2006

AbstractConjugated linoleic acid (CLA), a mixture of positional and geometric isomers of octadecadienoic acid, has been shown to inhibit experimentally induced atherosclerosis in rabbits and also to cause significant regression of pre‐established atheromatous lesions in rabbits. The two major CLA isomers (cis9,trans11 and trans10,cis12), now available at 90% purity, have been tested individually for their anti‐atherogenic or lesion regression potency. The two major isomers and the mixture were fed for 90 d to rabbits fed 0.2% cholesterol. Atherosclerosis was inhibited significantly by all three preparations. The two CLA isomers and the isomer mix were also fed (1.0%) as part of a cholesterol‐free diet for 90 d to rabbits bearing atheromatous lesions produced by feeding an atherogenic diet. A fourth group was maintained on a cholesterol‐free diet. On the CLA‐free diet atherosclerosis was exacerbated by 35%. Reduction of severity of atheromatous lesions was observed to the same extent in all three CLA‐fed groups. The average reduction of severity in the three CLA‐fed groups was 26±2% compared with the first control (atherogenic diet) and 46±1% compared with the regression diet. Insofar as individual effects on atherosclerosis were concerned, there was no difference between the CLA mix and the cis9,trans11 and trans10,cis12 isomers. They inhibit atherogenesis by 50% when fed as a component of a semipurified diet containing 0.2% cholesterol; and when fed as part of a cholesterol‐free diet, they reduce established lesions by 26%. Reduction of atheromata to the observed extent by dietar means alone is noteworthy.
Gestational age and birth weight in relation to n−3 fatty acids among inuit (Canada)
Authors: Lucas Michel , Dewailly Éric , Muckle Gina , Ayotte Pierre , Bruneau Suzanne , Gingras Suzanne , Rhainds Marc , Holub Bruce J. 
Published: November 2006

AbstractSeafood consumption during pregnancy carries both benefits (high n−3 FA intake) and risks (exposure to environmental contaminants) for the developing fetus. We determined the impacts of marine n−3 FA and environmental contaminants on gestational age (GA) of Nunavik women and the anthropometric characteristics of their newborns. FA and contaminant (polychlorinated biphenyls and mercury) concentrations were measured in cord plasma of Nuvavik newborns (n=454) and compared with those of a group of newborns (n=29) from southern Québec. Data were collected from hospital records and birth certificates. In Nunavik newborns, arachidonic acid (AA) was two times lower (P<0.0001), whereas DHA concentration, the Σn−3/Σn−6 ratio, and the percentage of n−3 highly unsaturated FA (HUFA) (of the total HUFA) were three times higher (P<0.0001) compared with southern Québec newborns. After controlling for confounders, GA and birth weight were higher by 5.4 d [95% confidence interval (CI): 0.7–10.1] and 77 g (95% CI: −64 to 217) in the third tertile of percentage of n−3 HUFA (of the total HUFA) as compared with the first tertile. There was no evidence that contaminants had negative effects on GA or birth weight. In this seafood‐eating population, an increase in the proportion of n−3 HUFA (of the total HUFA), measured in umbilical cord plasma phospholipids, was associated with a significantly longer GA.
Supplementation and delivery of n−3 fatty acids through spray‐dried milk reduce serum and liver lipids in rats
Authors: Ramaprasad T. R. , Baskaran V. , Sambaiah K. , Lokesh B. R. 
Published: November 2006

AbstractIndian diets comprising staples such as cereals, millets, and pulses provide 4.8 energy % from linoleic acid (18∶2n−6) but fail to deliver adequate amounts of n−3 FA. Consumption of long‐chain n−3 PUFA such as EPA (20∶5n−3) and DHA (22∶6n−3) is restricted to those who consume fish. The majority of the Indian population, however, are vegetarians needing additional dietary sources of n−3 PUFA. The present work was designed to use n−3 FA‐enriched spray‐dired milk powder to provide n−3 FA. Whole milk was supplemented with linseed oil to provide α‐linolenic acid (LNA, 18∶3n−3), with fish oil to provide EPA and DHA, or with groundnut oil (GNO), which is devoid of n−3 PUFA, and then spray‐dired. Male Wistar rats were fed the spray‐dired milk formulations for 60 d. The rats given formulations containing n−3 FA showed significant increases (P<0.001) in the levels of LNA or EPA/DHA in the serum and in tissue as compared with those fed the GNO control formulation. Rats fed formulations containing n−3 FA had 30–35% lower levels of serum total cholesterol and 25–30% lower levels of serum TAG than control animals. Total cholesterol and TAG in the livers of rats fed the formulations containing n−3 FA were lower by 18–30% and 11–18%, respectively, compared with control animals. This study showed that spray‐dried milk formulations supplemented with n−3 FA are an effective means of improving dietary n−3 FA intake, which may decrease the risk factors associated with cardiovascular disease.
Diet and lipoprotein oxidation: Analysis of oxidized triacylglycerols in pig lipoproteins
Authors: Suomela Jukka‐Pekka , Ahotupa Markku , Sjövall Olli , Kurvinen Juha‐Pekka , Kallio Heikki 
Published: November 2006

AbstractOxidized lipoproteins have a recognized role in atherogenesis, but molecular‐level research on oxidized lipids in lipoproteins and the effect of diet on these molecules have been limited. In the present study, the effects of three sunflower seed oil diets differing in oxidation levels (PV in oils 1, 84, and 223 mequiv O2/kg) on lipoprotein lipid oxidation in growing pigs were investigated. The emphasis was on the investigation of oxidized TAG molecules found in chylomicrons and VLDL. A method based on RP‐HPLC and electrospray ionization‐MS was used for the analysis of oxidized TAG molecules. The baseline diene conjugation method was used for the estimation of in vivo levels of lipoprotein lipid oxidation. Several oxidized TAG structures were found in the samples. These products consisted of TAG molecules with a hydroxy, an epoxy, or a keto group attached to a FA, and of TAG molecules containing an aldehyde structure derived from a FA. The lipoprotein lipids and TAG were more oxidized in the pigs fed on the most oxidized oil compared with those fed on nonoxidized oil. Oxidation of dietary fat was reflected in the lipoprotein oxidation. New, detailed information on oxidized TAG molecules of chylomicrons and VLDL was obtained.
Synthesis, spectroscopic, and biological studies of novel estolides derived from anticancer active 4‐O‐podophyllotoxinyl 12‐hydroxyl‐octadec‐Z‐9‐enoate
Authors: Mustafa Jamal , Khan Shabana I. , Ma Guoyi , Walker Larry A. , Khan Ikhlas A. 
Published: November 2006

AbstractPodophyllotoxin is a well‐known natural antitumor agent with severe side effects, which led us to synthesize its numerous analogs in search of product(s) of improved therapeutic potential. Here, we report an efficient method for the synthesis of a series of 4‐O‐podophyllotoxin estolides with spectral characteristics and their biological studies. The OH of a known molecule, 4‐O‐podophyllotoxinyl 12‐hydroxyl‐octadec‐Z‐9‐enoate 2, was coupled with the carboxylic groups of different FA with the help of dicyclohexylcarbodiimide and dimethyl aminopyridine (catalyst) to produce high yields of their respective C4α‐estolides 3–11. Spectroscopic techniques, particularly 1H and 13CNMR, proved to be suitable tools to characterize the new compounds. These molecules of greater lipophilic character were tested for their in vitro cytotoxicity against four human solid tumors, one human leukemia cell, and one noncancerous cell. Compounds 4–6 and 11 showed moderate antileukemic activity; unexpectedly, none were found to be active against solid tumors. Estolides were also investigated for their in vitro activity against tubulin and topoisomerase II proteins. All the compounds showed inhibition of the catalytic activity of topoisomerase II, whereas 6–8 also inhibited tubulin polymerization. These results suggest the need for further screening of these molecules against a larger panel of cancerous cells.
Antibacterial and xanthine oxidase inhibitory cerebrosides from Fusarium sp. IFB‐121, and endophytic fungus in Quercus variabilis
Authors: Shu R. G. , Wang F. W. , Yang Y. M. , Liu Y. X. , Tan R. X. 
Published: November 2006

AbstractTwo antibacterial and xanthine oxidase inhibitory cerebrosides, one of which is chemically new, were characterized from the chloroform‐methanol (1∶1) extract of Fusarium sp. IFB‐121, an endophytic fungus in Quercus variabilis. By means of chemical and spectral methods [IR, electrospray ionization MS (ESI‐MS), tandem ESI‐MS, 1H and 13C NMR, distortionless enhancement by polarization transfer, COSY, heteronuclear multiple‐quantum coherence, heteronuclear multiple‐bond correlation, and 2‐D nuclear Overhauser effect correlation spectroscopy], the structure of the new metabolite named fusaruside was established as (2S,2′R,3R,3′E,4E,8E,10E)‐1‐O‐β‐d‐glucopyranosyl‐2‐N‐(2′‐hydroxy‐3′‐octadecenoyl)‐3‐hydroxy‐9‐methyl‐4,8,10‐sphingatrienine, and the structure of the other was identified as (2S,2′R,3R,3′E,4E,8E)‐1‐O‐β‐d‐glucopyranosyl‐2‐N‐(2′‐hydroxy‐3′‐octadecenoyl)‐3‐hydroxy‐9‐methyl‐4,8‐sphingadienine. Both new and known cerebrosides, although inactive to Trichophyton rubrum and Candida albicans, showed strong antibacterial activities against Bacillus subtilis, Escherichia coli, and Pseudomonas fluorescens, with their minimum inhibitory concentrations being 3.9, 3.9, and 1.9 μg/mL, and 7.8, 3.9, and 7.8 μg/mL, respectively. Furthermore, both metabolites were inhibitory to xanthine oxidase, with the IC50 value of fusaruside being 43.8±3.6 μM and the known cerebroside being 55.5±1.8 μM.
Quantitative determination of low density lipoprotein oxidation by FTIR and chemometric analysis
Authors: Lam Henry S. , Proctor Andrew , Nvalala John , Morris Manford D. , Smith W. Grady 
Published: November 2006

AbstractThis study was conducted to develop a quantitative FTIR spectroscopy method to measure LDL lipid oxidation products and determine the effect of oxidation on LDL lipid and protein. In vitro LDL oxidation at 37°C for 1 h produced a range of conjugated diene (CD) (0.14–0.26 mM/mg protein) and carbonyl contents (0.9–3.8 μg/g protein) that were used to produce calibration sets. Spectra were collected from the calibration set and partial least squares regression was used to develop calibration models from spectral regions 4000‐650, 3750‐3000, 1720‐1500, and 1180‐935 cm−1 to predict CD and carbonyl contents. The optimal models were selected based on their standard error of prediction (SEP), and the selected models were performance‐tested with an additional set of LDL spectra. The best models for CD prediction were derived from spectral regions 4000‐650 and 1180‐935 cm−1 with the lowest SEP of 0.013 and 0.013 mM/mg protein, respectively. The peaks at 1745 (cholesterol and TAG ester C=O stretch), 1710 (carbonyl C‐O stretch), and 1621 cm−1 (peptide C=O stretch) positively correlated with LDL oxidation. FTIR and chemometrics revealed protein conformation changes during LDL oxidation and provided a simple technique that has potential for rapidly observing structural changes in human LDL during oxidation and for measuring primary and secondary oxidation products.