排序方式: 共有73条查询结果,搜索用时 281 毫秒
11.
Purification and characterization of Dolichos lablab lectin 总被引:1,自引:0,他引:1
The mannose/glucose-binding Dolichos lablab lectin (designated DLL) has
been purified from seeds of Dolichos lablab (hyacinth bean) to
electrophoretic homogeneity by affinity chromatography on an ovalbumin-
Sepharose 4B column. The purified lectin gave a single symmetric protein
peak with an apparent molecular mass of 67 kDa on gel filtration
chromatography, and five bands ranging from 10 kDa to 22 kDa upon SDS-PAGE.
N-Terminal sequence analysis of these bands revealed subunit heterogeneity
due to posttranslational proteolytic truncation at different sites mostly
at the carboxyl terminus. The carbohydrate binding properties of the
purified lectin were investigated by three different approaches:
hemagglutination inhibition assay, quantitative precipitation inhibition
assay, and ELISA. On the basis of these studies, it is concluded that the
Dolichos lablab lectin has neither an extended carbohydrate combining site,
nor a hydrophobic binding site adjacent to it. The carbohydrate combining
site of DLL appears to most effectively accommodate a nonreducing terminal
alpha-d-mannosyl unit, and to be complementary to the C-3, C-4, and C-6
equatorial hydroxyl groups of alpha-d-mannopyranosyl and
alpha-d-glucopyranosyl residues. DLL strongly precipitates murine IgM but
not IgG, and the recent finding that this lectin interacts specifically
with NIH 3T3 fibroblasts transfected with the Flt3 tyrosine kinase receptor
and preserves human cord blood stem cells and progenitors in a quiescent
state for prolonged periods in culture, make this lectin a valuable tool in
biomedical research.
相似文献
12.
13.
Pascale Simard Hugo Galarneau Sébastien Marois Daniel Rusu Caroline D Hoemann Patrice E Poubelle Hani El-Gabalawy Maria JG Fernandes 《Arthritis research & therapy》2009,11(3):R74-10
Introduction
Osteoarthritis is characterized by the progressive destruction of cartilage in the articular joints. Novel therapies that promote resurfacing of exposed bone in focal areas are of interest in osteoarthritis because they may delay the progression of this disabling disease in patients who develop focal lesions. Recently, the addition of 80% deacetylated chitosan to cartilage microfractures was shown to promote the regeneration of hyaline cartilage. The molecular mechanisms by which chitosan promotes cartilage regeneration remain unknown. Because neutrophils are transiently recruited to the microfracture site, the effect of 80% deacetylated chitosan on the function of neutrophils was investigated. Most studies on neutrophils use preparations of chitosan with an uncertain degree of deacetylation. For therapeutic purposes, it is of interest to determine whether the degree of deacetylation influences the response of neutrophils to chitosan. The effect of 95% deacetylated chitosan on the function of neutrophils was therefore also investigated and compared with that of 80% deacetylated chitosan. 相似文献14.
Manuel J. Lpez‐Rodríguez Ignacio Peralta‐Maraver Brunella Gaetani Carmen E. Sainz‐Cantero Romolo Fochetti J. Manuel Tierno de Figueroa 《International Review of Hydrobiology》2012,97(6):485-496
In this work we present the results of a one‐year study on the macroinvertebrate community in an intermittent stream in southern Spain. We have studied the taxonomic composition, diversity and food web monthly in order to consider temporal variability in these parameters. More than 60 macroinvertebrate taxa have been recorded in the stream, but they do not cohabit at the same time. Many of them join the community at the beginning of the wet period. Afterwards, some new taxa incorporate but some others disappear. This leads to huge fluctuations in the diversity of the community and in the food web of different sampling dates. These variations are linked to environmental disturbances, mainly to flow peaks and minimums. From a relatively well structured, but simple, food web at the beginning of the wet period, it can be seen how several trophic levels disappear with time, and how several organisms change or extend their trophic function within it. We relate these variations to the intermediate disturbance hypothesis and discuss the resilience of the community of this intermittent stream (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
Cecilia JG de Almeida Jean-Fran?ois Jasmin Francesco Del Galdo Michael P Lisanti 《Cell cycle (Georgetown, Tex.)》2013,12(14):2248-2254
Caveolar domains act as platforms for the organization of molecular complexes involved in signal transduction. Caveolin proteins, the principal structural components of caveolae, have been involved in many cellular processes. Caveolin-1 (Cav-1) and caveolin-2 (Cav-2) are highly expressed in the lung. Cav-1-deficient mice (Cav-1−/−) and Cav-2-deficient mice (Cav-2−/−) exhibit severe lung dysfunction attributed to a lack of Cav-2 expression. Recently, Cav-1 has been shown to regulate lung fibrosis in different models. Here, we show that Cav-2 is also involved in modulation of the fibrotic response, but through distinct mechanisms. Treatment of wild-type mice with the pulmonary fibrosis-inducer bleomycin reduced the expression of Cav-2 and its phosphorylation at tyrosine 19. Importantly, Cav-2−/− mice, but not Cav-1−/− mice, were more sensitive to bleomycin-induced lung injury in comparison to wild-type mice. Bleomycin-induced lung injury was characterized by alveolar thickening, increase in cell density, and extracellular matrix deposition. The lung injury observed in bleomycin-treated Cav-2−/− mice was not associated with alterations in the TGF-β signaling pathway and/or in the ability to produce collagen. However, apoptosis and proliferation were more prominent in lungs of bleomycin-treated Cav-2−/− mice. Since Cav-1−/− mice also lack Cav-2 expression and show a different outcome after bleomycin treatment, we conclude that Cav-1 and Cav-2 have distinct roles in bleomycin induced-lung fibrosis, and that the balance of both proteins determines the development of the fibrotic process. 相似文献
16.
Two distinct conformational states define the interaction of human RAD51‐ATP with single‐stranded DNA 下载免费PDF全文
Andrea Candelli Edwige B Garcin Mauro Modesti Luca Pellegrini Gijs JL Wuite Erwin JG Peterman 《The EMBO journal》2018,37(7)
An essential mechanism for repairing DNA double‐strand breaks is homologous recombination (HR). One of its core catalysts is human RAD51 (hRAD51), which assembles as a helical nucleoprotein filament on single‐stranded DNA, promoting DNA‐strand exchange. Here, we study the interaction of hRAD51 with single‐stranded DNA using a single‐molecule approach. We show that ATP‐bound hRAD51 filaments can exist in two different states with different contour lengths and with a free‐energy difference of ~4 kBT per hRAD51 monomer. Upon ATP hydrolysis, the filaments convert into a disassembly‐competent ADP‐bound configuration. In agreement with the single‐molecule analysis, we demonstrate the presence of two distinct protomer interfaces in the crystal structure of a hRAD51‐ATP filament, providing a structural basis for the two conformational states of the filament. Together, our findings provide evidence that hRAD51‐ATP filaments can exist in two interconvertible conformational states, which might be functionally relevant for DNA homology recognition and strand exchange. 相似文献
17.
The alcohol dehydrogenase (Adh) region from five planitibia subgroup
species of Hawaiian picture-wing Drosophila has been cloned. A total of 15
kb of DNA in and around the Adh gene has been compared among the five
species. Genetic distances were calculated to determine evolutionary
relationships. These distances agree with previous distances determined by
protein polymorphism and DNA hybridization techniques and can be
interpreted in terms of specific island colonization and speciation
(founder) events over the past 5 Myr. Examination of the restriction maps
of the cloned Adh region from the five species shows many instances of
small deletions, insertion of a transposable element in D. heteroneura, and
the existence of a highly variable region on the 3' side of the Adh gene.
Clustering relationships and rates of DNA change are calculated and
compared with the relationship found for other species of Drosophila.
相似文献
18.
Mario D Cordero Manuel De Miguel Ana M Moreno Fernández Inés M Carmona López Juan Garrido Maraver David Cotán Lourdes Gómez Izquierdo Pablo Bonal Francisco Campa Pedro Bullon Plácido Navas José A Sánchez Alcázar 《Arthritis research & therapy》2010,12(1):R17
Introduction
Fibromyalgia is a chronic pain syndrome with unknown etiology. Recent studies have shown some evidence demonstrating that oxidative stress may have a role in the pathophysiology of fibromyalgia. However, it is still not clear whether oxidative stress is the cause or the effect of the abnormalities documented in fibromyalgia. Furthermore, the role of mitochondria in the redox imbalance reported in fibromyalgia also is controversial. We undertook this study to investigate the role of mitochondrial dysfunction, oxidative stress, and mitophagy in fibromyalgia.Methods
We studied 20 patients (2 male, 18 female patients) from the database of the Sevillian Fibromyalgia Association and 10 healthy controls. We evaluated mitochondrial function in blood mononuclear cells from fibromyalgia patients measuring, coenzyme Q10 levels with high-performance liquid chromatography (HPLC), and mitochondrial membrane potential with flow cytometry. Oxidative stress was determined by measuring mitochondrial superoxide production with MitoSOX™ and lipid peroxidation in blood mononuclear cells and plasma from fibromyalgia patients. Autophagy activation was evaluated by quantifying the fluorescence intensity of LysoTracker™ Red staining of blood mononuclear cells. Mitophagy was confirmed by measuring citrate synthase activity and electron microscopy examination of blood mononuclear cells.Results
We found reduced levels of coenzyme Q10, decreased mitochondrial membrane potential, increased levels of mitochondrial superoxide in blood mononuclear cells, and increased levels of lipid peroxidation in both blood mononuclear cells and plasma from fibromyalgia patients. Mitochondrial dysfunction was also associated with increased expression of autophagic genes and the elimination of dysfunctional mitochondria with mitophagy.Conclusions
These findings may support the role of oxidative stress and mitophagy in the pathophysiology of fibromyalgia. 相似文献19.
Arjan D van Zuilen Ingeborgh van der Tweel Peter J Blankestijn Michiel L Bots Marjolijn van Buren Marc AGJ ten Dam Karin AH Kaasjager Peter JG van de Ven Gerald Vervoort Louis-Jean Vleming Gerry Ligtenberg Jack FM Wetzels 《Trials》2006,7(1):1-9
Background
Patients with chronic kidney disease (CKD) are at a greatly increased risk of developing cardiovascular disease. Recently developed guidelines address multiple risk factors and life-style interventions. However, in current practice few patients reach their targets. A multifactorial approach with the aid of nurse practitioners was effective in achieving treatment goals and reducing vascular events in patients with diabetes mellitus and in patients with heart failure. We propose that this also holds for the CKD population.Design
MASTERPLAN is a multicenter randomized controlled clinical trial designed to evaluate whether a multifactorial approach with the aid of nurse-practicioners reduces cardiovascular risk in patients with CKD. Approximately 800 patients with a creatinine clearance (estimated by Cockcroft-Gault) between 20 to 70 ml/min, will be included. To all patients the same set of guidelines will be applied and specific cardioprotective medication will be prescribed. In the intervention group the nurse practitioner will provide lifestyle advice and actively address treatment goals. Follow-up will be five years. Primary endpoint is the composite of myocardial infarction, stroke and cardiovascular mortality. Secondary endpoints are cardiovascular morbidity, overall mortality, decline of renal function, change in markers of vascular damage and change in quality of life. Enrollment has started in April 2004 and the study is on track with 700 patients included on October 15th, 2005. This article describes the design of the MASTERPLAN study. 相似文献20.
Peters RJ Bonnier HJ Bredee JJ 《International journal of cardiovascular interventions》1999,2(3):153-162
In 1996 the Minister of Public Health, Welfare and Sports in The Netherlands published a 'Planning Decree Special Interventions in the Heart'. She requested from the professional organizations guidelines for the indications for interventions in the heart. A working group was formed with representatives from the Dutch professional organizations for cardiology and thoracic surgery, to address this issue for patients with coronary artery disease. The working group confirmed the need to discuss all patients who are considered for either elective or emergency revascularization during a multidisciplinary consultation in (or with) one of the specialized Dutch hospitals. During this meeting of the 'heart team', at least one interventional cardiologist and one thoracic surgeon should be present. There are three possible outcomes of the heart team's consultations for each patient: drug therapy only ('conservative management'), coronary surgery or catheter intervention. For each case, the team should indicate the expected benefit, the risk of the intervention, the urgency and the estimated waiting time. The guidelines presented in this paper address these issues for three patient categories: stable angina pectoris, unstable angina pectoris and acute myocardial infarction. 相似文献