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101.
Adelmann K Frey D Riedl E Koeppel H Pfister F Peters V Schmitt CP Sternik P Hofmann S Zentgraf HW Navis G van den Born J Bakker SJ Krämer BK Yard BA Hauske SJ 《Amino acids》2012,43(1):143-151
Serum carnosinase (CN-1) measurements are at present mainly performed by assessing enzyme activity. This method is time-consuming, not well suited for large series of samples and can be discordant to measurements of CN-1 protein concentrations. To overcome these limitations, we developed sandwich ELISA assays using different anti-CN-1 antibodies, i.e., ATLAS (polyclonal IgG) and RYSK173 (monoclonal IgG1). With the ATLAS-based assay, similar amounts of CN-1 were detected in serum and both EDTA and heparin plasma. The RYSKS173-based assay detected CN-1 in serum in all individuals at significantly lower concentrations compared to the ATLAS-based assay (range: 0.1-1.8 vs. 1-50 μg/ml, RYSK- vs. ATLAS-based, P<0.01). CN-1 detection with the RYSK-based assay was increased in EDTA plasma, albeit at significantly lower concentrations compared to ATLAS. In heparin plasma, CN-1 was also poorly detected with the RYSK-based assay. Addition of DTT to serum increased the detection of CN-1 in the RYSK-based assay almost to the levels found in the ATLAS-based assay. Both ELISA assays were highly reproducible (R: 0.99, P<0.01 and R: 0.93, P<0.01, for the RYSK- and ATLAS-based assays, respectively). Results of the ATLAS-based assay showed a positive correlation with CN-1 activity (R: 0.62, P<0.01), while this was not the case for the RYSK-based assay. However, there was a negative correlation between CN-1 activity and the proportion of CN-1 detected in the RYSK-based assay, i.e., CN-1 detected with the RYSK-based assay/CN-1 detected with the ATLAS-based assay × 100% (Spearman-Rang correlation coefficient: -0.6, P<0.01), suggesting that the RYSK-based assay most likely detects a CN-1 conformation with low CN-1 activity. RYSK173 and ATLAS antibodies reacted similarly in Western blot, irrespective of PNGase treatment. Binding of RYSK173 in serum was not due to differential N-glycosylation as demonstrated by mutant CN-1 cDNA constructs. In conclusion, our study demonstrates a good correlation between enzyme activity and CN-1 protein concentration in ELISA and suggests the presence of different CN-1 conformations in serum. The relevance of these different conformations is still elusive and needs to be addressed in further studies. 相似文献
102.
103.
Oliver Poetz Dr. Sibylle Hoeppe Markus F. Templin Dieter Stoll Thomas O. Joos 《Proteomics》2009,9(6):1518-1523
MS‐based strategies are key technologies for identifying proteins in proteomic research. Despite significant improvements in recent years efficient fractionation processes of target analytes remain major bottlenecks in MS‐based protein analysis. Immunoaffinity‐based sample fractionation strategies have shown their potential for the enrichment of analyte peptides of interest, but only small numbers of analytes can be quantified in one experiment. The lack of appropriate capture reagents limits the application of immunoaffinity‐based approaches and only biased biomarker discovery approaches are possible. This perspective discusses the current status of immunoaffinity MS‐based approaches and introduces a novel concept that uses group specific anti‐peptide antibodies – Triple X Proteomics Antibodies – for the enrichment of signature peptides. Classes of peptides with identical termini can be fractionated based on TXP immunoaffinity enrichment steps and can subsequently be identified using established tandem MS procedures. Based on bioinformatic algorithms minimal sets of TXP epitopes can be specified, that cover a wide range of given proteome landscapes of one or even several different species. This opens the possibility to use a minimal number of TXP antibodies as a universal toolbox for general immunoaffinity‐based approaches in proteome analysis. 相似文献
104.
105.
Gubsch M Roscher C Gleixner G Habekost M Lipowsky A Schmid B Schulze ED Steinbeiss S Buchmann N 《Plant, cell & environment》2011,34(6):895-908
Plant and soil nitrogen isotope ratios (δ15N) were studied in experimental grassland plots of varying species richness. We hypothesized that partitioning of different sources of soil nitrogen among four plant functional groups (legumes, grasses, small herbs, tall herbs) should increase with diversity. Four years after sowing, all soils were depleted in 15N in the top 5 cm whereas in non‐legume plots soils were enriched in 15N at 5–25 cm depth. Decreasing foliar δ15N and Δδ15N (= foliar δ15N ? soil δ15N) values in legumes indicated increasing symbiotic N2 fixation with increasing diversity. In grasses, foliar Δδ15N also decreased with increasing diversity suggesting enhanced uptake of N depleted in 15N. Foliar Δδ15N values of small and tall herbs were unaffected by diversity. Foliar Δδ15N values of grasses were also reduced in plots containing legumes, indicating direct use of legume‐derived N depleted in 15N. Increased foliar N concentrations of tall and small herbs in plots containing legumes without reduced foliar δ15N indicated that these species obtained additional mineral soil N that was not consumed by legumes. These functional group and species specific shifts in the uptake of different N sources with increasing diversity indicate complementary resource use in diverse communities. 相似文献
106.
Bundschuh RA Essler M Dinges J Berchtenbreiter C Mariss J Martínez-Möller A Delso G Hohberg M Nekolla SG Schulz D Ziegler SI Schwaiger M 《Molecular imaging》2010,9(6):319-328
Positron emission tomography-computed tomography (PET-CT) is superior compared to stand-alone PET in evaluation of malignancies. Few studies have employed high-resolution structural information to correct PET. We designed a semiautomatic algorithm using CT and PET to obtain a partial volume corrected (PVC) standardized uptake value (SUV) and a combined morphologic and functional parameter (multimodal SUV) for lymph node assessment. Lesions were segmented by a semiautomatic algorithm in CT images. Lesion volume was used for PVC and for calculating the multimodal SUV. The method was applied to 47 lymph nodes (30 patients) characterized as suspicious in 18F-fluorodeoxyglucose-PET-CT. In phantoms, PVC improved significantly the measured uptake of the lesion. In patients, 36 lymph nodes could be segmented without problems; in 11 lesions, a manual interaction was necessary. SUVs before PVC (mean 1.29) increased significantly (p < .0005) after PVC (mean 2.8). If SUV 2.5 was used as a threshold value to distinguish between benign and malignant lesions, 11 of the 47 lesions changed from benign to malignant after the PVC. The mean multimodal SUV was 0.39 mL for the benign lesions and 4.47 mL for the malignant lesions. In this work we presented a method for quantitative analysis of lymph nodes in PET-CT. PVC leads to significant differences in SUV. 相似文献
107.
Strunze S Engelke MF Wang IH Puntener D Boucke K Schleich S Way M Schoenenberger P Burckhardt CJ Greber UF 《Cell host & microbe》2011,10(3):210-223
Many viruses deliver their genomes into the host cell nucleus for replication. However, the size restrictions of the nuclear pore complex (NPC), which regulates the passage of proteins, nucleic acids, and solutes through the nuclear envelope, require virus capsid uncoating before viral DNA can access the nucleus. We report a microtubule motor kinesin-1-mediated and NPC-supported mechanism of adenovirus uncoating. The capsid binds to the NPC filament protein Nup214 and kinesin-1 light-chain Klc1/2. The nucleoporin Nup358, which is bound to Nup214/Nup88, interacts with the kinesin-1 heavy-chain Kif5c to indirectly link the capsid to the kinesin motor. Kinesin-1 disrupts capsids docked at Nup214, which compromises the NPC and dislocates nucleoporins and capsid fragments into the cytoplasm. NPC disruption increases nuclear envelope permeability as indicated by the nuclear influx of large cytoplasmic?dextran polymers. Thus, kinesin-1 uncoats viral DNA?and compromises NPC integrity, allowing viral genomes nuclear access to promote infection. 相似文献
108.
Bendz H Ruhland SC Pandya MJ Hainzl O Riegelsberger S Braüchle C Mayer MP Buchner J Issels RD Noessner E 《The Journal of biological chemistry》2007,282(43):31688-31702
Heat shock proteins (HSPs) have shown promise for the optimization of protein-based vaccines because they can transfer exogenous antigens to dendritic cells and at the same time induce their maturation. Great care must be exercised in interpretating HSP-driven studies, as by-products linked to the recombinant generation of these proteins have been shown to mediate immunological effects. We generated highly purified human recombinant Hsp70 and demonstrated that it strongly enhances the cross-presentation of exogenous antigens resulting in better antigen-specific T cell stimulation. Augmentation of T cell stimulation was a direct function of the degree of complex formation between Hsp70 and peptides and correlated with improved antigen delivery to endosomal compartments. The Hsp70 activity was independent of TAP proteins and was not inhibited by exotoxin A or endosomal acidification. Consequently, Hsp70 enhanced cross-presentation of various antigenic sequences, even when they required different post-uptake processing and trafficking, as exemplified by the tumor antigens tyrosinase and Melan-A/MART-1. Furthermore, Hsp70 enhanced cross-presentation by different antigen-presenting cells (APCs), including dendritic cells and B cells. Importantly, enhanced cross-presentation and antigen-specific T cell activation were observed in the absence of innate signals transmitted by Hsp70. As Hsp70 supports the cross-presentation of different antigens and APCs and is inert to APC function, it may show efficacy in various settings of immune modulation, including induction of antigen-specific immunity or tolerance. 相似文献
109.
Matrix-degrading podosomes in smooth muscle cells 总被引:1,自引:0,他引:1
Lener T Burgstaller G Crimaldi L Lach S Gimona M 《European journal of cell biology》2006,85(3-4):183-189
Activation of protein kinase C by phorbol esters triggers the remodelling of the actin cytoskeleton and the formation of podosomes in smooth muscle cells (SMCs). Regional control of actin dynamics at specialised microdomains results in a local reduction in contractile forces. The molecular basis for this local inhibition of contractility includes the clustering of cortactin during podosome formation (which precedes the rapid, local dispersion of myosin, tropomyosin and h1 calponin), and the specific recruitment of 110-kDa actin filament-associated protein (AFAP-110) and 190-kDa Rho-specific GTPase-activating protein (p190RhoGAP) to the microdomains. Podosome formation also correlates with cell polarisation, the induction of cell motility, and local degradation of the extracellular matrix. These findings may provide explanations for the complex mechanisms underlying SMC invasion in the course of the development of atherosclerotic lesions and restenosis, and support the concept that matrix degradation and the concomitant engagement of the molecular machinery initiating actin-based cell motility drive tissue invasion in smooth muscle. 相似文献
110.
Nicole Scheuing Reinhard W. Holl Gerd Dockter Julia M. Hermann Sibylle Junge Cordula Koerner-Rettberg Lutz Naehrlich Christina Smaczny Doris Staab Gabriela Thalhammer Silke van Koningsbruggen-Rietschel Manfred Ballmann 《PloS one》2014,9(11)