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191.
The halotolerant alga Dunaliella salina is a recognized model photosynthetic organism for studying plant adaptation to high salinity. The adaptation mechanisms involve major changes in the proteome composition associated with energy metabolism and carbon and iron acquisition. To clarify the molecular basis for the remarkable resistance to high salt, we performed a comprehensive proteomics analysis of the plasma membrane. Plasma membrane proteins were recognized by tagging intact cells with a membrane-impermeable biotin derivative. Proteins were resolved by two-dimensional blue native/SDS-PAGE and identified by nano-LC-MS/MS. Of 55 identified proteins, about 60% were integral membrane or membrane-associated proteins. We identified novel surface coat proteins, lipid-metabolizing enzymes, a new family of membrane proteins of unknown function, ion transporters, small GTP-binding proteins, and heat shock proteins. The abundance of 20 protein spots increased and that of two protein spots decreased under high salt. The major salt-regulated proteins were implicated in protein and membrane structure stabilization and within signal transduction pathways. The migration profiles of native protein complexes on blue native gels revealed oligomerization or co-migration of major surface-exposed proteins, which may indicate mechanisms of stabilization at high salinity. 相似文献
192.
Šerić Jelaska Lucija Ivanković Tatalović Lara Kostanjšek Fran Kos Tomislav 《BioControl》2022,67(3):275-286
BioControl - Biodiversity in the Mediterranean is undergoing a decline resulting in reduced ecosystem service provisions. Here we analysed the functional diversity of ground beetles in... 相似文献
193.
Říčan Oldřich Říčanová Štěpánka Dragová Klára Piálek Lubomír Almirón Adriana Casciotta Jorge 《Hydrobiologia》2019,832(1):331-354
Hydrobiologia - We address the diversity of two species groups of the cichlid genus Gymnogeophagus in the Middle Paraná basin using molecular phylogeography and traditional morphological... 相似文献
194.
A red blood cell (RBC) performs its function of adequately carrying respiratory gases in blood by its volume being ~60% of that of a sphere with the same membrane area. For this purpose, human and most other vertebrate RBCs regulate their content of potassium (K+) and sodium (Na+) ions. The focus considered here is on K+ efflux through calcium-ion (Ca2+)-activated Gárdos channels. These channels open under conditions that allow Ca2+ to enter RBCs through Piezo1 mechanosensitive cation-permeable channels. It is postulated that the fraction of open Piezo1 channels depends on the RBC shape as a result of the curvature-dependent Piezo1-bilayer membrane interaction. The consequences of this postulate are studied by introducing a simple model of RBC osmotic behavior supplemented by the dependence of RBC membrane K+ permeability on the reduced volume (i.e., the ratio of cell volume to its maximal possible volume) of RBC discoid shapes. It is assumed that because of its intrinsic curvature and strong interaction with the surrounding membrane, Piezo1 tends to concentrate in the dimple regions of these shapes, and the fraction of open Piezo1 channels depends on the membrane curvature in that region. It is shown that the properties of the described model can provide the basis for the formation of the negative feedback loop that interrelates cell volume and its content of potassium ions. The model predicts the relation, valid for each cell in an RBC population, between RBC volume and membrane area, thus explaining the large value of the measured membrane area versus the volume correlation coefficient. The mechanism proposed here for RBC volume regulation is in accord with the loss of this correlation in RBCs of Piezo1 knockout mice. 相似文献
195.
Yan-Hui Wang Hao-Yang Wu Dávid Rédei Qiang Xie Yan Chen Ping-Ping Chen Zhuo-Er Dong Kai Dang Jakob Damgaard Pavel Štys Yan-Zhuo Wu Jiu-Yang Luo Xiao-Ya Sun Viktor Hartung Stefan M. Kuechler Yang Liu Hua-Xi Liu Wen-Jun Bu 《Cladistics : the international journal of the Willi Hennig Society》2019,35(1):42-66
The phylogeny of true bugs (Hemiptera: Heteroptera), one of the most diverse insect groups in terms of morphology and ecology, has been the focus of attention for decades with respect to several deep nodes between the suborders of Hemiptera and the infraorders of Heteroptera. Here, we assembled a phylogenomic data set of 53 taxa and 3102 orthologous genes to investigate the phylogeny of Hemiptera–Heteroptera, and both concatenation and coalescent methods were used. A binode-control approach for data filtering was introduced to reduce the incongruence between different genes, which can improve the performance of phylogenetic reconstruction. Both hypotheses (Coleorrhyncha + Heteroptera) and (Coleorrhyncha + Auchenorrhyncha) received support from various analyses, in which the former is more consistent with the morphological evidence. Based on a divergence time estimation performed on genes with a strong phylogenetic signal, the origin of true bugs was dated to 290–268 Ma in the Permian, the time in Earth's history with the highest concentration of atmospheric oxygen. During this time interval, at least 1007 apomorphic amino acids were retained in the common ancestor of the extant true bugs. These molecular apomorphies are located in 553 orthologous genes, which suggests the common ancestor of the extant true bugs may have experienced large-scale evolution at the genome level. 相似文献
196.
197.
Extracellular oxidative enzyme production and PAH removal in soil by exploratory mycelium of white rot fungi 总被引:15,自引:0,他引:15
Čeněk Novotný Pavla Erbanová Václav Šašek Alena Kubátová Tomáš Cajthaml Elke Lang Jürgen Krahl František Zadražil 《Biodegradation》1999,10(3):159-168
Selected strains of three species of white rot fungi, Pleurotus ostreatus, Phanerochaete chrysosporium and Trametes versicolor,
were grown in sterilized soil from straw inocula. The respective colonization rates and mycelium density values decreased
in the above mentioned order. Three- and four-ringed PAHs at 50 ppm inhibited growth of fungi in soil to some extent. The
activities of fungal MnP and laccase (units per g dry weight of straw or soil), extracted with 50 mM succinate-lactate buffer
(pH 4.5), were 5 to 20-fold higher in straw compared to soil. The enzyme activities per g dry soil in P. ostreatus and T.
versicolor were similar, in contrast to P. chrysosporium, where they were extremely low. Compared to the aerated controls,
P. ostreatus strains reduced the levels of anthracene, pyrene and phenanthrene by 81–87%, 84–93% and 41–64% within 2 months,
respectively. During degradation of anthracene, all P. ostreatus strains accumulated anthraquinone. PAH removal rates in P.
chrysosporium and T. versicolor soil cultures were much lower. 相似文献
198.
Synthesis of hexose-related imidazolidinones: Novel glycation products in the Maillard reaction 总被引:1,自引:0,他引:1
Carbohydrate-peptide esters which mimic the reactivity of sugar 6-phosphates in nonenzymatic glycations were used as model compounds for the study of the Maillard reaction in vitro. We found that intramolecular cyclization of the monosaccharide ester in which the sugar moiety (D-glucose or D-galactose) is linked, through the C-6 hydroxy group, to the C-terminal carboxy group of the endogenous opioid pentapeptide leucine-enkephalin, in methanol as the solvent, resulted in the formation of imidazolidinone diastereoisomers having cis or trans relative geometry of the substituents at the imidazolidinone ring moiety. The diastereoisomeric imidazolidinones were separated and each transformed by hydrolysis into the corresponding D-gluco- and D-galacto-related imidazolidinone products of leucine-enkephalin. Along with the previous evidence that, from the same sugar-peptide esters by changing the reaction conditions Amadori rearrangement products could be obtained [Horvat et al. (1998) J Chem Soc Perkin Trans 1:99–13], the presented results point to the possibility that similar carbohydrate-related imidazolidinones may also be generated in the early stage of the Maillard reaction in vivo. 相似文献
199.
Oblak M Prezelj A Pecar S Solmajer T 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(11-12):880-886
Several novel thiol-reactive clenbuterol analogues were coupled in high yield with bovine serum albumin (BSA). After labelling of unreacted cysteines with maleimide spin label (MiSL), the yield of the coupling reaction was determined by electron paramagnetic resonance (EPR) spectroscopy and spectral analysis. Two spin-probe populations with different mobility states were quantitatively determined. Molecular dynamics was used to model the structure of clenbuterol analogues and spin label conjugated to BSA and recognition of conjugates by anti-clenbuterol antibodies was demonstrated. The recognition of BSA-A, BSA-C and BSA-S conjugates with monoclonal and polyclonal anti-clenbuterol (mCLB-Ab and rCLB-Ab) antibodies was an indication, that chlorine substituents on the aromatic ring of clenbuterol derivatives are not necessary for the binding of antibodies to the conjugates. These results confirmed the importance of the tert-butylamino group as a part of the epitope and contribute to the understanding of the recognition process with anti-clenbuterol antibodies. 相似文献
200.