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Two different families of hydroxyproline-rich glycoproteins in melon callus: biochemical and immunochemical studies 总被引:5,自引:3,他引:2
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Two different families of hydroxyproline-rich glycoproteins, HRGP1 and HRGP2, have been isolated from melon callus and separated by ion exchange chromatography on CM-sepharose. HRGP1 corresponds to an arabinogalactan protein. The sugar portion of HRGP1 accounts for 94% of the molecule and contains galactose (66%) and arabinose (34%); these residues are present as polysaccharide side chains attached to hydroxyproline. Hydroxyproline is the main amino acid residue (46%) of the protein moiety. The arabinogalactan protein nature of HRGP1 has been checked by its ability to positively react with the β-glucosyl Yariv antigen; the 3H-labeled deglycosylated HRGP1 also called HRP1 migrates upon electrophoresis as a single band of molecular weight 76,000. HRGP2 was fractionated by affinity chromatography on heparin-Ultrogel into three different glycoproteins, HRGP2a,2b and 2c. Two of these glycoproteins behave as polycations (HRGP2b and 2c) and are chemically distinct from HRGP2a. HRGP2b is the most abundant component and contains 41% protein and 50% sugar. Hydroxyproline, lysine, tyrosine, and arabinose are the most prominent residues of their respective moiety. The glycosylation pattern of hydroxyproline indicates that HRGP2b is related to and possibly a precursor of the wall HRGP; as in melon cell wall HRGP, Hyp-Ara3 predominates, and small amounts of a putative Hyp-Ara5 a hitherto unreported hyp-arabinoside, are recorded. The molecular weight of HRP2b, the protein portion of HRGP2b is 55,000 ± 5,000, as estimated after deglycosylation of the molecule with trifluoromethane sulfonic acid. Antibodies have been raised against HRGP2b and HRP2b. Immunodiffusion shows that each antigen (HRGP2b or HRP2b) reacts with its own IgG, and cross-reacts with the heterologous IgG, thereby indicating the presence of common (unglycosylated) and specific (glycosylated and deglycosylated) epitopes. The arabinogalactan protein HRGP1 is not recognized by either antibody and HRGP2b does not react with the Yariv antigen. Immunoprecipitation of 3H-labeled HRP1 and HRP2b in the presence of goat antirabbit IgG, followed by gel electrophoresis, allows to recover HRP2b only. Again, HRP2b is immunoprecipitated by the two antisera. 相似文献
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M Bomba D Ciavardelli E Silvestri L MT Canzoniero R Lattanzio P Chiappini M Piantelli C Di Ilio A Consoli S L Sensi 《Cell death & disease》2013,4(5):e612
Recent studies have shown that type 2 diabetes mellitus (T2DM) is a risk factor for cognitive dysfunction or dementia. Insulin resistance is often associated with T2DM and can induce defective insulin signaling in the central nervous system as well as increase the risk of cognitive impairment in the elderly. Glucagone like peptide-1 (GLP-1) is an incretin hormone and, like GLP-1 analogs, stimulates insulin secretion and has been employed in the treatment of T2DM. GLP-1 and GLP-1 analogs also enhance synaptic plasticity and counteract cognitive deficits in mouse models of neuronal dysfunction and/or degeneration. In this study, we investigated the potential neuroprotective effects of long-term treatment with exenatide, a GLP-1 analog, in two animal models of neuronal dysfunction: the PS1-KI and 3xTg-AD mice. We found that exenatide promoted beneficial effects on short- and long-term memory performances in PS1-KI but not in 3xTg-AD animals. In PS1-KI mice, the drug increased brain lactate dehydrogenase activity leading to a net increase in lactate levels, while no effects were observed on mitochondrial respiration. On the contrary, exenatide had no effects on brain metabolism of 3xTg-AD mice. In summary, our data indicate that exenatide improves cognition in PS1-KI mice, an effect likely driven by increasing the brain anaerobic glycolysis rate. 相似文献
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Documentation of use patterns of plants across national boundaries is of relevance in understanding the importance of plant resources to livelihood strategies of different ethnic groups. Plant resources have gained prominence as a natural asset through which families derive food, firewood, income, medicines and timber, enabling particularly poor communities to achieve self-sufficiency. The objective of this study was to investigate the trends in plant usage in South Africa and Zimbabwe. An ethnobotanical investigation was conducted between January 2012 and January 2013 in the Limpopo Province, South Africa and the Midlands Province, Zimbabwe. The study used questionnaire surveys and interviews with a total of 143 participants to explore plant use patterns in South Africa and Zimbabwe. A total of 98 plant species were identified, with Zimbabwe contributing 70 species and 47 species from South Africa. The uses were classified into 15 categories, major use categories were firewood, food plants, medicine and timber. Food plant was a major plant use category in Zimbabwe, contributing 55.1%, followed by medicinal plants (36.8%), firewood (35.7%) and timber (31.6%). In contrast, firewood was the major plant use category in South Africa, contributing 18.4%, followed by food plants (17.3%), medicinal (14.3%) and timber (1.0%). Comparison of the two countries demonstrated remarkable differences in plant use patterns. The results showed that rural households in Zimbabwe were more reliant on plant resources than their counterparts in South Africa. Such a trend could be attributed to a close relationship between the local people, and their natural and agricultural environment leading to a rich knowledge base on plants, plant use and related practices. This comparative analysis strengthens the firm belief that utilization of plant resources represents an important shared heritage, preserved over the centuries, which must be exploited in order to provide further new and useful body of ethnobotanical knowledge. 相似文献
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Wither J Cai YC Lim S McKenzie T Roslin N Claudio JO Cooper GS Hudson TJ Paterson AD Greenwood CM Gladman D Pope J Pineau CA Smith CD Hanly JG Peschken C Boire G;CaNIOS Investigators Fortin PR 《Arthritis research & therapy》2008,10(5):R108-13
Introduction
Systemic lupus erythematosus is a genetically complex disease. Currently, the precise allelic polymorphisms associated with this condition remain largely unidentified. In part this reflects the fact that multiple genes, each having a relatively minor effect, act in concert to produce disease. Given this complexity, analysis of subclinical phenotypes may aid in the identification of susceptibility alleles. Here, we used flow cytometry to investigate whether some of the immune abnormalities that are seen in the peripheral blood lymphocyte population of lupus patients are seen in their first-degree relatives.Methods
Peripheral blood mononuclear cells were isolated from the subjects, stained with fluorochrome-conjugated monoclonal antibodies to identify various cellular subsets, and analyzed by flow cytometry.Results
We found reduced proportions of natural killer (NK)T cells among 367 first-degree relatives of lupus patients as compared with 102 control individuals. There were also slightly increased proportions of memory B and T cells, suggesting increased chronic low-grade activation of the immune system in first-degree relatives. However, only the deficiency of NKT cells was associated with a positive anti-nuclear antibody test and clinical autoimmune disease in family members. There was a significant association between mean parental, sibling, and proband values for the proportion of NKT cells, suggesting that this is a heritable trait.Conclusions
The findings suggest that analysis of cellular phenotypes may enhance the ability to detect subclinical lupus and that genetically determined altered immunoregulation by NKT cells predisposes first-degree relatives of lupus patients to the development of autoimmunity. 相似文献29.
A report on the First International Symposium of the Austrian Proteomics Platform, Seefeld, Austria, 26-29 January 2004. 相似文献
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Herbert C Jacquet C Borel C Esquerre-Tugaye MT Dumas B 《The Journal of biological chemistry》2002,277(32):29125-29131