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1.
Andrea Dichlberger Stefanie Schlager Katariina Maaninka Wolfgang J. Schneider Petri T. Kovanen 《Journal of lipid research》2014,55(12):2471-2478
Human mast cells (MCs) contain TG-rich cytoplasmic lipid droplets (LDs) with high arachidonic acid (AA) content. Here, we investigated the functional role of adipose TG lipase (ATGL) in TG hydrolysis and the ensuing release of AA as substrate for eicosanoid generation by activated human primary MCs in culture. Silencing of ATGL in MCs by siRNAs induced the accumulation of neutral lipids in LDs. IgE-dependent activation of MCs triggered the secretion of the two major eicosanoids, prostaglandin D2 (PGD2) and leukotriene C4 (LTC4). The immediate release of PGD2 from the activated MCs was solely dependent on cyclooxygenase (COX) 1, while during the delayed phase of lipid mediator production, the inducible COX-2 also contributed to its release. Importantly, when ATGL-silenced MCs were activated, the secretion of both PGD2 and LTC4 was significantly reduced. Interestingly, the inhibitory effect on the release of LTC4 was even more pronounced in ATGL-silenced MCs than in cytosolic phospholipase A2-silenced MCs. These data show that ATGL hydrolyzes AA-containing TGs present in human MC LDs and define ATGL as a novel regulator of the substrate availability of AA for eicosanoid generation upon MC activation. 相似文献
2.
Daw-Yang Hwang Stefan Kohl Xueping Fan Asaf Vivante Stefanie Chan Gabriel C. Dworschak Julian Schulz Albertien M. van Eerde Alina C. Hilger Heon Yung Gee Tracie Pennimpede Bernhard G. Herrmann Glenn van de Hoek Kirsten Y. Renkema Christoph Schell Tobias B. Huber Heiko M. Reutter Neveen A. Soliman Natasa Stajic Radovan Bogdanovic Elijah O. Kehinde Richard P. Lifton Velibor Tasic Weining Lu Friedhelm Hildebrandt 《Human genetics》2015,134(8):905-916
3.
Simple phagemid-based system for generating allele replacements in Escherichia coli. 总被引:12,自引:5,他引:7 下载免费PDF全文
We describe a phagemid-based system for rapidly generating chromosomal allele replacements in two steps. The system utilizes simple vector-determined selection procedures for each step and requires only that the target strain be male and sup+ (nonsuppressing for amber mutations). 相似文献
4.
Schuster Martina Tewary Gargi Bao Xuanwen Subedi Prabal Hauck Stefanie M. Olsen Ann Karin Eide Dag Markus Trott Klaus Rüdiger Götz Sebastian Atkinson Michael J. Rosemann Michael 《Radiation and environmental biophysics》2021,60(4):689-689
Radiation and Environmental Biophysics - 相似文献
5.
Yi-Wen Chiu Sangwon Suh Stephan Pfister Stefanie Hellweg Annette Koehler 《The International Journal of Life Cycle Assessment》2012,17(1):16-24
Purpose
Though the development of biofuel has attracted numerous studies for quantifying potential water demand applying life cycle thinking, the impacts of biofuel water consumption still remain unknown. In this study, we aimed to quantify ecological impact associated with corn-based bioethanol water consumption in Minnesota in responding to different refinery expansion scenarios by applying a life cycle impact assessment method. 相似文献6.
7.
A Maurer J O McIntyre S Churchill S Fleischer 《The Journal of biological chemistry》1985,260(3):1661-1669
D-beta-Hydroxybutyrate dehydrogenase is a lipid-requiring enzyme which is localized on the inner face of the mitochondrial inner membrane. The apodehydrogenase, i.e. the purified enzyme devoid of lipid, has been purified from beef heart mitochondria and as such is inactive. It can be reactivated by insertion into phospholipid vesicles containing lecithin. Proteolytic digestion with different proteases has been carried out to obtain insight into the orientation of the enzyme in the membrane and to assess the extent of immersion of the protein into the phospholipid bilayer. Digestion of the apodehydrogenase with either trypsin, chymotrypsin, Staphylococcus aureus protease, thermolysin, carboxypeptidases A and Y, or Pronase (from Streptomyces griseus) leads to loss of activity, as assayed with phospholipid. Limited digestion with carboxypeptidase results in complete inactivation. Of the proteases tested, only Pronase and chymotrypsin cleave and inactivate the enzyme inserted into phospholipid vesicles (enzyme-phospholipid complex). For the enzyme-phospholipid complex, the loss of activity with Pronase digestion follows a single exponential decay to less than 10% of the initial activity. With chymotrypsin digestion, the staining intensity of the original approximately 31,500-dalton polypeptide decreases more rapidly than the loss of enzymic activity. The enzyme-phospholipid complex, after limited cleavage with chymotrypsin, retains enzymic activity and resonance energy transfer from protein to bound NADH and an approximately 26,000-dalton polypeptide is observed. Phospholipid alters the cleavage pattern with both chymotrypsin and Pronase, and the rate of inactivation of the enzyme-phospholipid complex is slowed in the presence of NAD(H). Moreover, the rate of inactivation of the apodehydrogenase with chymotrypsin is diminished approximately 3-fold in the presence of NAD+. Digestion of submitochondrial vesicles with either trypsin, chymotrypsin, or Pronase rapidly inactivates D-beta-hydroxybutyrate dehydrogenase; the addition of NAD+ or NADH, together with dithiothreitol and increased salt (to 50 mM), decreases the rate of inactivation, and with trypsin, virtually eliminates inactivation.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
8.
Stefanie Mädler 《Analytical biochemistry》2010,398(1):123-125
In order to clarify whether arginine has a promoting effect on the acylation of hydroxyl groups of serine, threonine, or tyrosine by homobifunctional cross-linking agents in aqueous solution, we carried out systematic experiments with model peptides, comparing relative reaction yields with covalently protected and unprotected arginines by MALDI-MS. The guanidinium group could be demonstrated to contribute to the reactivity of hydroxyl groups toward N-hydroxysuccinimide esters and catalyze the nucleophilic substitution, probably via hydrogen bonds. 相似文献
9.
The parasitoid nanoflagellate (PNF) Pirsonia diadema is hostspecific for the marine centric diatom Coscinodiscus spp. Experimentsshowed that flagellates significantly prefer C. wailesii overC.granii as host species (interspecific selectivity). This preferencewas independent of light conditions (dark, irradiance of 10and 70 µmol m2 s1) and temperature (10 and15C). Among unicellular host diatoms, the infection behaviourwas selective for individual cells: already infected C.graniicells were more attractive for further flagellate attachmentthan non-infected cells (intraspecific selectivity). Individualcells ( 相似文献
10.
Stefanie Wagner Isabel Sorg Matteo Degiacomi Laure Journet Matteo Dal Peraro Guy R. Cornelis 《Molecular microbiology》2009,71(3):692-701
The length of the Yersinia injectisome needle is determined by the protein YscP, which could act as a molecular ruler. The analysis of the correlation between the size of YscP and the needle length in seven wild-type strains of Yersinia enterocolitica reinforced this hypothesis but hinted that the secondary structure of YscP might influence needle length. Hence, 11 variants of YscP515 were generated by multiple Pro or Gly substitutions. The needle length changed in inverse function of the helical content, indicating that not only the number of residues but also their structure controls length. Taking the secondary motifs into account, Pro/Gly-variants were subjected to in silico modelling to simulate the extension of YscP upon needle growth. The calculated lengths when the helical content is preserved correlated strikingly with the measured needle length, with a constant difference of ∼29 nm, which corresponds approximately to the size of the basal body. These data support the ruler model and show that the functional ruler has a helical structure. 相似文献