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271.
The ɛ‐Amino Group of Protein Lysine Residues Is Highly Susceptible to Nonenzymatic Acylation by Several Physiological Acyl‐CoA Thioesters
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Zeljko Simic Dr. Matthias Weiwad Dr. Angelika Schierhorn Dr. Clemens Steegborn Dr. Mike Schutkowski 《Chembiochem : a European journal of chemical biology》2015,16(16):2337-2347
Mitochondrial enzymes implicated in the pathophysiology of diabetes, cancer, and metabolic syndrome are highly regulated by acetylation. However, mitochondrial acetyltransferases have not been identified. Here, we show that acetylation and also other acylations are spontaneous processes that depend on pH value, acyl‐CoA concentration and the chemical nature of the acyl residue. In the case of a peptide derived from carbamoyl phosphate synthetase 1, the rates of succinylation and glutarylation were up to 150 times than for acetylation. These results were confirmed by using the protein substrate cyclophilin A (CypA). Deacylation experiments revealed that SIRT3 exhibits deacetylase activity but is not able to remove any of the succinyl groups from CypA, whereas SIRT5 is an effective protein desuccinylase. Thus, the acylation landscape on lysine residues might largely depend on the enzymatic activity of specific sirtuins, and the availability and reactivity of acyl‐CoA compounds. 相似文献
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Laundry washing has been extensively studied; laundry drying has been much less investigated. Nevertheless, there are indications that the drying process takes considerably more energy than the washing process. It is, therefore, the task of this study to gather European-wide consumer behaviour on washing and drying practices and to use this knowledge to estimate the energy consumption for the washing and drying processes. With an online questionnaire answered by over 2,000 households, the washing and drying behaviour of European consumers is analysed. The results also confirm the relevance of the drying process’ energy consumption for countries where the drying is normally seen as ‘done by the sun’! 相似文献
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Aoife L. McCarthy Yvonne C. O’Callaghan Susanne Neugart Charles O. Piggott Alan Connolly Marcel A.K. Jansen Angelika Krumbein Monika Schreiner Richard J. FitzGerald Nora M. O’Brien 《Food chemistry》2013
The hydroxycinnamic acid (HA) content of starting barley for brewers’ spent grains (BSG), whole BSG and phenolic extracts from BSG was measured using high performance liquid chromatography (HPLC) and correlated with antioxidant potential. The effect of BSG phenolic extracts on antioxidant activity of fruit beverages was also assessed (using the total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The concentration of HA present in barley extract and BSG was in the order of ferulic acid (FA), p-coumaric acid (p-CA) derivatives, FA derivatives, p-CA, caffeic acid (CA) and CA derivatives. Results suggested that brewing and roasting decreased the HA content. Antioxidant activity was significantly (P < 0.05) correlated with caffeic acid (R2 = 0.8309) and total HA (R2 = 0.3942) concentrations. Addition of extracts to fruit beverages resulted in a significant (P < 0.05) increase in antioxidant activity of cranberry juice, measured by the FRAP assay. In vitro digestion significantly (P < 0.05) reduced TPC, DPPH and FRAP activity of the fruit beverages. 相似文献
277.
More and more car manufacturers are now demanding clear coats with improved scratch resistance from their paint suppliers. Some motor companies have developed their own tests, some have chosen a test developed by a paint supplier and others are still looking for their optimum test. The opinion prevails that there should be one test which covers all aspects of realistic damage. However, microscopic photographs and reflow experiments show that two kinds of scratches occur in reality, abrasive as well as non-abrasive, renewable ones. Different standard clear coat systems have different sensitivities to both scratch types. In the scratch tests the rating of the clear coats is divergent, because the ratio of both sorts of scratches differs. We have developed a set of two tests, where each test mainly generates one scratch type. These tests, together with physico-chemical measurements (glass transition onset temperature Tg, laser optical profile scanning, indentation depths) lead to a deeper insight into scratch phenomena. One way to develop a clear coat which is resistant against all kinds of scratching damage is described. 相似文献
278.
Bernhard Gehl Andreas Frömsdorf Vesna Aleksandrovic Thomas Schmidt Angelika Pretorius Jan‐Ingo Flege Sigrid Bernstorff Andreas Rosenauer Jens Falta Horst Weller Marcus Bäumer 《Advanced functional materials》2008,18(16):2398-2410
The interaction of nitrogen, oxygen, and hydrogen plasmas with spin‐coated arrays of colloidal cobalt–platinum particles was investigated with a large variety of microscopic and spectroscopic techniques. It could be demonstrated that the organic ligands of the nanoparticles can be completely removed. Yet, due to the short (~1.6 nm) interparticle distances within the layers, strong degradation and sintering effects are observed after hydrogen and nitrogen plasma treatments. In the case of oxygen plasma, the shape and size of the individual particles are unaffected and can be preserved, even if a short hydrogen plasma is subsequently applied to reduce the particles back to their metallic state. Nevertheless, the mesoscopic order of the particle arrays is slightly decreased as observed by the breakup of larger ordered areas into smaller domains forming island–trench structures. Probing the surface chemistry of the particles with temperature programmed desorption, a rather complex surface chemistry is found to result from the plasma treatments. The first TPD spectrum after the cleaning process with oxygen and subsequent hydrogen plasmas reveals that the particles are loaded with adsorbed and implanted hydrogen. After removal of this hydrogen, subsequent TPD spectra using CO as a probe molecule, show broad signals between 190 and 360 K pointing to nonmetallic surface properties. While the platinum was found to be completely reduced, XPS measurements reveal a remaining fraction of oxidic cobalt species which are enriched at the surface. Thus, although the structure of the close‐packed Co–Pt nanoparticle arrays can be qualitatively preserved during plasma‐based ligand removal, the treatment leads to a complex materials system the chemical properties of which are influenced by the particle components, the substrate, and the plasma media. 相似文献
279.
Reducing water temperatures in the wash phase of a washing programme and increasing the overall cycle durations are the latest trends in decreasing energy consumption of washing programmes, particularly for the so-called Standard programmes. This paper discusses the importance of saving energy in laundry washing, reasonable cycle duration for consumers and the link between saving energy and the duration of the wash cycle from a consumer point of view. This enables manufacturers to design appliances which are appreciated by the users. Information on consumers’ washing behaviour, experiences, habits and opinions concerning wash cycle duration was collected through a semi-representative survey in 11 European countries in 2015, with more than 5000 participants. The primary outcome of the study is that European consumers are willing to save water and energy in a laundry washing but are reluctant to use long programme cycles since they do not believe that the long cycles could be energy-saving. 相似文献
280.
Zischka H Larochette N Hoffmann F Hamöller D Jägemann N Lichtmannegger J Jennen L Müller-Höcker J Roggel F Göttlicher M Vollmar AM Kroemer G 《Analytical chemistry》2008,80(13):5051-5058
A pathological increase of the permeability of the mitochondrial membranes may culminate in the irreversible rupture of the mitochondrial outer membrane. Such a permeability transition is lethal because it results in the release of death-inducing molecules from mitochondria and/or metabolic failure. Current methods to assess this outer membrane damage are mostly indirect or scarcely representative of the overall mitochondrial population. Here we present an analytical and preparative approach using free flow electrophoresis to directly distinguish rat liver mitochondria that have undergone the permeability transition from unaffected organelles or from organelles that are damaged to a minor degree. Mitochondrial populations, which considerably differ in outer membrane integrity or cytochrome c content, were separated by this means. We further show that the relative abundance of each population depends on the dose of the permeability transition inducer and the duration of the treatment time. Finally, we have employed this approach to investigate the impairment of mitochondria that were isolated from livers subjected to ischemia/reperfusion damage. 相似文献