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Light-induced modification of Photosystem II (PS II) complex was characterized in the cyanobacterium Synechococcus sp. PCC 7942 treated with either DCMU (a phenylurea PS II inhibitor) or BNT (a phenolic PS II inhibitor). The irradiance
response of photoinactivation of PS II oxygen evolution indicated a BNT-specific photoinhibition that saturated at relatively
low intensity of light. This BNT-specific process was slowed down under anaerobiosis, was accompanied by the oxygen-dependent
formation of a 39 kDa D1 protein adduct, and was not related to stable QA reduction or the ADRY effect. In the BNT-treated cells, the light-induced, oxygen-independent initial drop of PS II electron
flow was not affected by formate, an anion modifying properties of the PS II non-heme iron. For DCMU-treated cells, anaerobiosis
did not significantly affect PS II photoinactivation, the D1 adduct was not observed and addition of formate induced similar
initial decrease of PS II electron flow as in the BNT-treated cells. Our results indicate that reactive oxygen species (most
likely singlet oxygen) and modification of the PS II acceptor side are responsible for the fast BNT-induced photoinactivation
of PS II.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
157.
Schepelmann M Molcan L Uhrova H Zeman M Ellinger I 《Cellular and molecular neurobiology》2011,31(8):1257-1265
Melatonin is involved in blood pressure modulation in rats and humans. Some of the effects of melatonin are presumably mediated
via two G-protein-coupled receptors (MT1 and MT2), but the distribution of MT1 and MT2 in the cardiovascular system remains to be explored comprehensively. We investigated the expression of both the receptors
in the rat aorta on mRNA level by RT-PCR and real time RT-PCR as well as on protein level via western blotting and immunofluorescence
microscopy. We verified MT1 mRNA expression in the rat aorta and demonstrated the absence of MT2 mRNA in this vessel type. MT1 receptors were confirmed also at the protein level, and surprisingly they were preferentially localized to the tunica adventitia.
Since no daily changes in MT1 mRNA expression were detected, we suppose that the circadian changes in circulating melatonin concentrations are sufficient
to mediate circadian effects of melatonin in the aorta. The localization of MT1 in the tunica adventitia suggests an influence of melatonin on vasa vasorum function and signal transduction in the aorta
wall. 相似文献
158.
Summary Phytoalexins accumulated in selected woody plants in response to microbial attack or stress are reviewed and listed with respect to their chemical structure and probable biogenetic origin. The host-pathogen systems from which they have been isolated are described. The review also considers the antimicrobial activity of the phytoalexins to the causal pathogens and other microorganisms. 相似文献
159.
An integrated UASB-sludge digester system for raw domestic wastewater treatment in temperate climates 总被引:1,自引:0,他引:1
To improve the performance of an upflow anaerobic sludge blanket (UASB) reactor treating raw domestic wastewater under temperate climates conditions, the addition of a sludge digester to the process was investigated. With the decrease in temperature, the COD removal decreased from 78% at 28 °C to 42% at 10 °C for the UASB reactor operating alone at a hydraulic retention time of 6 h. The decrease was attributed to low hydrolytic activity at lower temperatures that reduced suspended matter degradation and resulted in solids accumulation in the top of the sludge blanket. Solids removed from the upper part of the UASB sludge were treated in an anaerobic digester. Based on sludge degradation kinetics at 30 °C, a digester of 0.66 l per liter of UASB reactor was design operating at a 3.20 days retention time. Methane produced by the sludge digester is sufficient to maintain the temperature at 30 °C. 相似文献
160.
The cell wall of the human pathogen Candida glabrata: differential incorporation of novel adhesin-like wall proteins 下载免费PDF全文
de Groot PW Kraneveld EA Yin QY Dekker HL Gross U Crielaard W de Koster CG Bader O Klis FM Weig M 《Eukaryotic cell》2008,7(11):1951-1964
The cell wall of the human pathogen Candida glabrata governs initial host-pathogen interactions that underlie the establishment of fungal infections. With the aim of identifying species-specific features that may directly relate to its virulence, we have investigated the cell wall of C. glabrata using a multidisciplinary approach that combines microscopy imaging, biochemical studies, bioinformatics, and tandem mass spectrometry. Electron microscopy revealed a bilayered wall structure in which the outer layer is packed with mannoproteins. Biochemical studies showed that C. glabrata walls incorporate 50% more protein than Saccharomyces cerevisiae walls and, consistent with this, have a higher mannose/glucose ratio. Evidence is presented that C. glabrata walls contain glycosylphosphatidylinositol (GPI) proteins, covalently bound to the wall 1,6-β-glucan, as well as proteins linked through a mild-alkali-sensitive linkage to 1,3-β-glucan. A comprehensive genome-wide in silico inspection showed that in comparison to other fungi, C. glabrata contains an exceptionally large number, 67, of genes encoding adhesin-like GPI proteins. Phylogenetically these adhesin-like proteins form different clusters, one of which is the lectin-like EPA family. Mass spectrometric analysis identified 23 cell wall proteins, including 4 novel adhesin-like proteins, Awp1/2/3/4, and Epa6, which is involved in adherence to human epithelia and biofilm formation. Importantly, the presence of adhesin-like proteins in the wall depended on the growth stage and on the genetic background used, and this was reflected in alterations in adhesion capacity and cell surface hydrophobicity. We propose that the large repertoire of adhesin(-like) genes of C. glabrata contributes to its adaptability and virulence. 相似文献