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Dolichyl phosphates of different chain length (C35, C55 , C75 , Dol-mixture of C90 , 95, 100, 105 and C110 ) were tested as lipid acceptors in transglycosylation reactions. In the absence of exogenously added dolichyl phosphates there were no differences in the rate of synthesis in liver of dolichyl phosphate mannose, dolichyl phosphate glucose and dolichyl pyrophosphate N-acetylglucosamine between normal and ethionine-treated animals. Addition of exogenous dolichyl phosphates of different chain length stimulated the synthesis of dolichyl phosphate mannose and dolichyl pyrophosphate N-acetyl-glucosamine 2 to 4 times depending on the chain length of dolichols , both in normal and ethionine-treated animals. In liver of ethionine-treated rats the formation of dolichyl phosphate glucose was not stimulated. Following ethionine treatment the concentration of free and esterified with fatty acids dolichols was increased. 相似文献
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E Swiezewska T Chojnacki W J Jankowski A K Singh J Olsson 《Biochimie et biologie cellulaire》1992,70(6):448-454
The long chain polyprenols composed of 30 and more isoprene units from leaves of plants belonging to the genera Potentilla and Rosa have been described. They occur in the form of fatty acid esters. The composition of polyprenol mixture was species dependent and its content reached ca. 0.5% wet weight. Large scale preparation of individual polyprenols from a natural polyprenol mixture was performed using time-extended liquid chromatography on the hydrophobic gel Lipidex-5000. 相似文献
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M Runquist J Ericsson A Thelin T Chojnacki G Dallner 《Biochemical and biophysical research communications》1992,186(1):157-165
The cytosolic fractions from rat liver, brain, kidney, spleen and testis demonstrate the capacity to synthesize two products from [3H]isopentenyl diphosphate, i.e., farnesyl diphosphate and geranylgeranyl diphosphate. The highest rate of geranylgeranyl diphosphate synthesis was found in brain, testis and spleen, accounting for up to 30% of the total incorporation of radioactivity under optimal conditions. In all tissues examined the geranylgeranyl diphosphate formed was identified as the trans,trans,trans-isomer. The ratio of geranylgeranyl diphosphate to farnesyl diphosphate produced was specific for the tissue investigated and could be altered by the addition of divalent cations. The results in this study demonstrate the presence of a specific trans,trans,trans-geranylgeranyl diphosphate synthetase showing high affinity for farnesyl diphosphate. 相似文献
8.
Wisniewska-Jarosinska M Poplawski T Chojnacki CJ Pawlowska E Krupa R Szczepanska J Blasiak J 《Molecular biology reports》2011,38(7):4603-4611
Dental composite materials contain polymers of methacrylates, which, due to mechanical abrasion and enzymatic action of saliva,
may release their monomers into oral cavity and the pulp. Moreover, polymerization is always incomplete and leaves usually
considerable fraction of free monomers. Mechanisms of the genotoxicity of methacrylate monomers have been rarely explored.
As the polymerization of a monomer is catalyzed by a co-monomer, their combined action should be considered. In the present
work, we investigated cytotoxic and genotoxic effects of urethane dimethacrylate (UDMA), often used as a monomer, at 1 mM,
and triethylene glycol dimethacrylate (TEGDMA), a typical co-monomer, at 5 mM singly and in combination. Experiments were
conducted on Chinese hamster ovary cells. Cell viability, apoptosis and cell cycle were assessed by flow cytometry, whereas
DNA damage was evaluated by plasmid conformation test and comet assay. Both compounds decreased the viability of the cells,
but did not induce strand breaks in an isolated plasmid DNA. However, both substances, either singly or in combination, damaged
DNA in CHO cells as evaluated by comet assay. Both compounds induced apoptosis, but a combined action of them led to a decrease
in the number of apoptotic cells. The combined action of UDMA and TEGDMA in the disturbance of cell cycle was lesser compared
to the action of each compound individually. Individually, though UDMA and TEGDMA may induce cytotoxic and genotoxic, however,
a combination of both does not produce a significant increase in these effects. 相似文献
9.
Background
Although simulation studies show that combining multiple breeds in one reference population increases accuracy of genomic prediction, this is not always confirmed in empirical studies. This discrepancy might be due to the assumptions on quantitative trait loci (QTL) properties applied in simulation studies, including number of QTL, spectrum of QTL allele frequencies across breeds, and distribution of allele substitution effects. We investigated the effects of QTL properties and of including a random across- and within-breed animal effect in a genomic best linear unbiased prediction (GBLUP) model on accuracy of multi-breed genomic prediction using genotypes of Holstein-Friesian and Jersey cows.Methods
Genotypes of three classes of variants obtained from whole-genome sequence data, with moderately low, very low or extremely low average minor allele frequencies (MAF), were imputed in 3000 Holstein-Friesian and 3000 Jersey cows that had real high-density genotypes. Phenotypes of traits controlled by QTL with different properties were simulated by sampling 100 or 1000 QTL from one class of variants and their allele substitution effects either randomly from a gamma distribution, or computed such that each QTL explained the same variance, i.e. rare alleles had a large effect. Genomic breeding values for 1000 selection candidates per breed were estimated using GBLUP modelsincluding a random across- and a within-breed animal effect.Results
For all three classes of QTL allele frequency spectra, accuracies of genomic prediction were not affected by the addition of 2000 individuals of the other breed to a reference population of the same breed as the selection candidates. Accuracies of both single- and multi-breed genomic prediction decreased as MAF of QTL decreased, especially when rare alleles had a large effect. Accuracies of genomic prediction were similar for the models with and without a random within-breed animal effect, probably because of insufficient power to separate across- and within-breed animal effects.Conclusions
Accuracy of both single- and multi-breed genomic prediction depends on the properties of the QTL that underlie the trait. As QTL MAF decreased, accuracy decreased, especially when rare alleles had a large effect. This demonstrates that QTL properties are key parameters that determine the accuracy of genomic prediction.Electronic supplementary material
The online version of this article (doi:10.1186/s12711-015-0124-6) contains supplementary material, which is available to authorized users. 相似文献10.
Lipoteichoic acid is an important microbe-associated molecular pattern of Lactobacillus rhamnosus GG
Claes Ingmar JJ Segers Marijke E Verhoeven Tine LA Dusselier Michiel Sels Bert F De Keersmaecker Sigrid CJ Vanderleyden Jos Lebeer Sarah 《Microbial cell factories》2012,11(1):1-8