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Catherine Ronin Herman van Halbeek Johannah GM Mutsaers Johannes F G Vliegenthart 《Glycoconjugate journal》1987,4(3):247-254
The lipid-linked precursor ofN-type glycoprotein oligosaccharides was isolated from porcine thyroid microsomes after in cubation with UDP[3H] Glucose. The carbohydrate was released from dolichol pyrophosphate by mild acid hydrolysis, purified by gel filtration and characterized by 500-MHz1H-NMR spectroscopy in combination with enzymatic degradation. The parent oligosaccharide was found to be Glc3Man9Glc-NAc2. The three glucose residues are present in the linear sequence Glcα1-2Glα1-3 Glc, the latter being α(1-3)-linked to one of the mannose residues. In order to establish the branch location of the triglucosyl unit, the parent compound was digested with jack-bean α-mannosidase. The oligosaccharide product was purified by gel filtration, and identified by1H-NMR as Glc3Man5GlcNAc2 lacking the mannose residues A, D2, B and D3. Therefore, the structure of the precursor oligosaccharide is as follows: $$\begin{gathered} c b a D_1 C 4 \hfill \\ Glc\alpha 1 - 2Glc\alpha 1 - 3Glc\alpha 1 - 3Man\alpha 1 - 2Man\alpha 1 - 2Man\alpha 1 \hfill \\ 3 \swarrow 3 2 1 \hfill \\ Man\alpha 1 - 2Man\alpha 1 Man\beta 1 - 4GlcNAc\beta 1 - 4GlcNAc \hfill \\ D_{2 } A 3 6 \hfill \\ Man\alpha 1 \hfill \\ 6 \hfill \\ Man\alpha 1 - 2Man\alpha 1 \nwarrow 4 \hfill \\ D_3 B \hfill \\ \end{gathered} $$ 相似文献
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E. J. Trione B. B. Krygier G. M. Banowetz J. M. Kathrein 《Journal of Plant Growth Regulation》1991,10(1):101-109
Seven monoclonal anti-zeatin riboside antibodies were characterized by radioimmunoassay (RIA) and found to measure femtomole (10–15 M) quantities (20 pg) of this cytokinin. The antibodies had different measuring ranges defined by the linear portion of the logit/log plots; slopes and intercepts of the line varied considerably between the antibodies. Competitive binding trials againstcis-zeatin riboside (cZR), dihydrozeatin riboside (diHZR), zeatin (Z), and isopentenyl adenosine (iPA) showed differences among the seven antibodies in their cross-reactivities towards these structurally related cytokinins. It was possible to combine selected antibodies to provide a mixture with a predictable measuring range and cross-reactivity; the ability to prepare a highly specific reagent in this manner with well-defined reactivity was noted and differences between monoclonal antibody and polyclonal antiserum probes for measurement of cytokinins were discussed.The research was supported by the Agricultural Research Service, U.S. Department of Agriculture, Technical Paper No. 7373 of the Oregon Agricultural Experiment Station. Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the U.S. Department of Agriculture and does not imply approval to the exclusion of other products that may also be available. 相似文献
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The Pacific Northwest (PNW), an important region for wheat production in the USA, is often subject to water deficits during sowing and grain filling. These deficits reduce the quality and yield of the crop. As a consequence, an important objective of breeding programs in the region is improving the genetic adaptation of wheat cultivars to drought stress. One response to dehydrative stresses is the accumulation of proteins called dehydrins, which are believed to protect membranes and macromolecules against denaturation. We characterized dehydrin accumulation in seedlings during drought stress and its correlation with stress tolerance during grain filling in seven wheat cultivars, 'Connie', 'Gene', 'TAM105', 'Rod', 'Hiller', 'Rhode', and 'Stephens'. A 24-kd dehydrin accumulated in seedlings under stress, but not in irrigated control plants. Connie, TAM105, and Gene started to accumulate dehydrins at the fourth day of stress, while the other cultivars showed dehydrins after twelve days of stress. This differential accumulation in seedlings was associated with stress tolerance at grain filling, characterized by a lower reduction in yield and in the rate of decrease in leaf water potential per day of stress. Connie, TAM105, Gene and Rod where the most tolerant cultivars. The results indicate that expression of this 24-kd dehydrin might serve as a rapid and non-destructive screening technique at the seedling stage. Even though the results are promising, selection experiments using a population segregating for stress tolerance are needed to test more conclusively whether this dehydrin can serve as a genetic marker for cultivars with tolerance to drought stress. 相似文献
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H.M. El-Nashaar S.M. Griffith J.J. Steiner G.M. Banowetz 《Bioresource technology》2009,100(14):3526-3531
Stands of native grasses along roadways, in buffer strips, riparian zones and grass prairies have potential utility as feedstock for bioenergy production. The sustainability of harvesting these stands is reliant, in part, on knowledge of the mineral concentration of the harvested grasses because removal of mineral nutrients such as phosphorus (P) and potassium (K) can impact subsequent biomass production and ecosystem services associated with these stands. Mineral content of biomass, particularly that of silicon (Si), chlorine (Cl), and sulfur (S) also impacts thermochemical conversion approaches that convert grasses into bioproducts. This study quantified Cl, S, Si, P and K in Bromus marginatus, Elymus glaucus, Poa secunda, Pseudoroegneria, Elymus lanceolatus, Elymus trachycaulus, Leymus cinereus, Leymus triticoides, and Pseudoroegneria spicata collected at three growth developmental stages from four plant introduction stations located in the western US. Differences (P ? 0.05) in mineral concentrations were associated with developmental stage, species, and location. Variability was greatest in Si concentrations which ranged from 1847 to 28620 mg kg−1, similar to those recorded in other grasses. Variability in Cl and S concentrations also occurred, but at less magnitude than that of Si. Concentrations of P and K, two mineral fertilizer components, varied approximately threefold among these grasses. Differences in mineral concentrations among these grasses were not completely dependent upon soil mineral content. Long-term evaluations of available soil mineral concentrations under contrasting management practices are needed to quantify how local conditions impact mineral cycling, and in turn, the sustainability of harvesting these stands. The data presented here establish baselines for these species in locations subject to contrasting environmental and microbiological conditions that affect mineral cycling and availability. 相似文献
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Sebastian Dolff Daniel Quandt Benjamin Wilde Thorsten Feldkamp Fan Hua Xin Cai Christof Specker Andreas Kribben Cees GM Kallenberg Oliver Witzke 《Arthritis research & therapy》2010,12(4):R150
Introduction
There is growing evidence that interleukin 17 (IL-17) producing T cells are involved in the pathogenesis of systemic lupus erythematosus (SLE). Previous studies showed that increased percentages of T-cell subsets expressing the costimulatory molecules CD80 and CD134 are associated with disease activity and renal involvement in SLE. The aim of this study was to investigate the distribution and phenotypical characteristics of IL-17 producing T-cells in SLE, in particular in patients with lupus nephritis, with emphasis on the expression of CD80 and CD134. 相似文献7.
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Arends S Brouwer E van der Veer E Groen H Leijsma MK Houtman PM Th A Jansen TL Kallenberg CG Spoorenberg A 《Arthritis research & therapy》2011,13(3):R94
Introduction
Identifying ankylosing spondylitis (AS) patients who are likely to benefit from tumor necrosis factor-alpha (TNF-α) blocking therapy is important, especially in view of the costs and potential side effects of these agents. Recently, the AS Disease Activity Score (ASDAS) has been developed to assess both subjective and objective aspects of AS disease activity. However, data about the predictive value of the ASDAS with respect to clinical response to TNF-α blocking therapy are lacking. The aim of the present study was to identify baseline predictors of response and discontinuation of TNF-α blocking therapy in AS patients in daily clinical practice. 相似文献9.
de Groot L Hinkema H Westra J Smit AJ Kallenberg CG Bijl M Posthumus MD 《Arthritis research & therapy》2011,13(6):R205
Introduction
Advanced glycation end products (AGEs) are produced and can accumulate during chronic inflammation, as might be present in patients with rheumatoid arthritis (RA). AGEs are involved in the development of cardiovascular disease. The aim of this study is to evaluate whether AGEs are increased in patients with long-standing RA and whether AGE accumulation is related to disease activity, disease severity and measures of (premature) atherosclerosis, such as endothelial activation, endothelial dysfunction and intima media thickness (IMT). 相似文献10.