654 research outputs found
Crystal structure of the catalytic fragment of murine poly(ADP-ribose) polymerase-2.
Poly(ADP-ribose) polymerase-1 (PARP-1) has become an important pharmacological target in the treatment of cancer due to its cellular role as a 'DNA-strand break sensor', which leads in part to resistance to some existing chemo- and radiological treatments. Inhibitors have now been developed which prevent PARP-1 from synthesizing poly(ADP-ribose) in response to DNA-breaks and potentiate the cytotoxicity of DNA damaging agents. However, with the recent discoveries of PARP-2, which has a similar DNA-damage dependent catalytic activity, and additional members containing the 'PARP catalytic' signature, the isoform selectivity and resultant pharmacological effects of existing inhibitors are brought into question. We present here the crystal structure of the catalytic fragment of murine PARP-2, at 2.8 A resolution, and compare this to the catalytic fragment of PARP-1, with an emphasis on providing a possible framework for rational drug design in order to develop future isoform-specific inhibitors
Large-scale Production And Purification Of Recombinant Protein From An Insect Cell/baculovirus System In Erlenmeyer Flasks: Application To The Chicken Poly(adp-ribose) Polymerase Catalytic Domain
A simple and inexpensive shaker/Erlenmeyer flask system for large-scale cultivation of insect cells is described and compared to a commercial spinner system. On the basis of maximum cell density, average population doubling time and overproduction of recombinant protein, a better result was obtained with a simpler and less expensive bioreactor consisting of Erlenmeyer flasks and an ordinary shaker waterbath. Routinely, about 90 mg of pure poly(ADP-ribose) polymerase catalytic domain was obtained for a total of 3 × 109 infected cells in three liters of culture.308923928Althaus, F.R., Richter, C., ADP-ribosylation of proteins. Enzymology and biological significance (1987) Molecular Biology, Biochemistry and Biophysics, 37, pp. 1-126Lautier, D., Lagueaux, J., Ménard, L., Poirier, G.C., Molecular and biochemical features of poly(ADP-ribose) metabolism (1993) Molecular and Cellular Biochemistry, 122, pp. 171-193Satoh, M.S., Lindahl, T., Role of poly(ADP-ribose) formation in DNA repair (1992) Nature, 356, pp. 356-358Molinete, M., Vermeulen, W., Bürkle, A., Ménissier-de Murcia, J., Küpper, J., Hoeijmakers, J., De Murcia, G., Overproduction of the poly(ADP-ribose) polymerase DNA-binding domain blocks alkylation-induced DNA repair synthesis in mammalian cells (1993) EMBO Journal, 5, pp. 2109-2117Masson, M., Rolli, V., Dantzer, F., Trucco, C., Schrieber, V., Fribourg, S., Molinete, M., De Murcia, G., Poly(ADP-ribose) polymerase: Structure-function relationship (1995) Biochimie, 77, pp. 456-461Suto, M.L., Suto, M.S., Inhibitors of poly(ADP-ribose) polymerase (ADPRP): Potential chemotherapeutic agents (1991) Drugs of the Future, 16, pp. 723-739Giner, H., Simonin, F., De Murcia, G., Ménissier-de Murcia, J., Overproduction and large-scale purification of the human poly(ADP-ribose) polymerase using a baculovirus expression system (1992) Gene, 114, pp. 279-283Simonin, F., Höfferer, L., Panzeter, P., Muller, S., De Murcia, G., Althaus, F.R., The carboxy-terminal domain of human poly(ADP-ribose) polymerase: Overproduction in Escherichia coli, large scale purification and characterization (1993) Journal of Molecular Biology, 268, pp. 13454-13461Murhammer, D.W., Review and patents literature. The use of insect cell cultures for recombinant protein synthesis: Engineering aspects (1991) Applied Biochemistry and Biotechnology, 31, pp. 283-310Goosen, M.F.A., Large-scale insect cell culture (1992) Current Opinion in Biotechnology, 3, pp. 99-104Kamen, A.A., Tom, R.L., Caron, A.W., Chavarie, C., Massie, B., Archambault, J., Culture of insect cells in a helical ribbon impeller bioreactor (1991) Biotechnology and Bioengineering, 38, pp. 619-628Van Lier, F.L.J., Van Den End, E.J., Gooijer, C.D., Vlak, J.M., Tramper, J., Continuous production of baculovirus in a cascade insect-cell reactor (1990) Applied Microbiology and Biotechnology, 33, pp. 43-47Power, J., Greenfield, P.F., Nielsen, L., Reid, S., Modelling the growth and protein production by insect cells following infection by a recombinant baculovirus in suspension culture (1992) Cytotechnology, 9, pp. 149-155Stavroulakis, D.A., Kalogerakis, N., Behie, L.A., Latrou, K., Kinetic data for the BM-5 insect line in repeated-batch suspension culture (1991) Biotechnology, 38, pp. 116-126Neutra, R., Levi, B.-Z., Shoham, Y., Optimization of protein-production by the baculovirus expression vector system in shake flasks (1992) Applied Microbiology and Biotechnology, 37, pp. 74-78Luckow, V.A., Summers, M.D., Signals important for high level expression of foreign genes in Autographa californica nuclear polyhedrosis virus expression vectors (1989) Virology, 170, pp. 31-39O'Reily, D.R., Miller, L.K., Luckow, V.A., (1992) Baculovirus Expression System: A Laboratory Manual, , Freeman, New YorkScott, R.L., Blanchard, J.H., Fergusson, C.H.R., Effects of oxygen on recombinant protein production by suspension cultures of Spodoptera frugiperda Sf9 insect cell (1992) Enzyme and Microbial Technology, 14, pp. 798-80
Large-scale production and purification of recombinant protein from an insect cell/baculovirus system in Erlenmeyer flasks: application to the chicken poly(ADP-ribose) polymerase catalytic domain
Frequency of tuberculous and non-tuberculous mycobacteria in HIV infected patients from Bogota, Colombia
BACKGROUND: The prevalence of infections by Mycobacterium tuberculosis and non-tuberculous Mycobacterium species in the HIV-infected patient population in Colombia was uncertain despite some pilot studies. We determined the frequency of isolation of Mycobacterium tuberculosis and of non-tuberculous Mycobacterium species in diverse body fluids of HIV-infected patients in Bogota, Colombia. METHODS: Patients who attended the three major HIV/AIDS healthcare centres in Bogota were prospectively studied over a six month period. A total of 286 patients were enrolled, 20% of them were hospitalized at some point during the study. Sixty four percent (64%) were classified as stage C, 25% as stage B, and 11% as stage A (CDC staging system, 1993). A total of 1,622 clinical samples (mostly paired samples of blood, sputum, stool, and urine) were processed for acid-fast bacilli (AFB) stain and culture. RESULTS: Overall 43 of 1,622 cultures (2.6%) were positive for mycobacteria. Twenty-two sputum samples were positive. Four patients were diagnosed with M. tuberculosis (1.4%). All isolates of M. tuberculosis were sensitive to common anti-tuberculous drugs. M. avium was isolated in thirteen patients (4.5%), but only in three of them the cultures originated from blood. The other isolates were obtained from stool, urine or sputum samples. In three cases, direct AFB smears of blood were positive. Two patients presented simultaneously with M. tuberculosis and M. avium. CONCLUSIONS: Non-tuberculous Mycobacterium infections are frequent in HIV infected patients in Bogota. The diagnostic sensitivity for infection with tuberculous and non-tuberculous mycobacteria can be increased when diverse body fluids are processed from each patient
Periodogram Connectivity of EEG Signals for the Detection of Dyslexia
Electroencephalography (EEG) signals provide an important source of information of brain activity at different areas. This information can be used to diagnose brain disorders according to different activation patterns found in controls and patients. This acquisition technology can be also used to explore the neural basis of less evident learning disabilities such as Developmental Dyslexia (DD). DD is a specific difficulty in the acquisition of reading skills not related to mental age or inadequate schooling, whose prevalent is estimated between 5% and 12% of the population. In this paper we propose a method to extract discriminative features from EEG signals based on the relationship among the spectral density at each channel. This relationship is computed by means of different correlation measures, inferring connectivity-like markers that are eventually selected and classified by a linear support vector machine. The experiments performed shown AUC values up to 0.7, demonstrating the applicability of the proposed approach for objective DD diagnosis
Poly[ADP-Ribose] Polymerase-1 Expression Is Related To Cold Ischemia, Acute Tubular Necrosis, and Delayed Renal Function In Kidney Transplantation
Cold ischemia time especially impacts on outcomes of expanded-criteria donor (ECD) transplantation. Ischemia-reperfusion (IR) injury produces excessive poly[ADP-Ribose] Polymerase-1 (PARP-1) activation. The present study explored the hypothesis that increased tubular expression of PARP-1 contributes to delayed renal function in suboptimal ECD kidney allografts and in non-ECD allografts that develop posttransplant acute tubular necrosis (ATN)
Prospecting environmental mycobacteria: combined molecular approaches reveal unprecedented diversity
Background: Environmental mycobacteria (EM) include species commonly found in various terrestrial and aquatic environments, encompassing animal and human pathogens in addition to saprophytes. Approximately 150 EM species can be separated into fast and slow growers based on sequence and copy number differences of their 16S rRNA genes. Cultivation methods are not appropriate for diversity studies; few studies have investigated EM diversity in soil despite their importance as potential reservoirs of pathogens and their hypothesized role in masking or blocking M. bovis BCG vaccine.
Methods: We report here the development, optimization and validation of molecular assays targeting the 16S rRNA gene to assess diversity and prevalence of fast and slow growing EM in representative soils from semi tropical and temperate areas. New primer sets were designed also to target uniquely slow growing mycobacteria and used with PCR-DGGE, tag-encoded Titanium amplicon pyrosequencing and quantitative PCR.
Results: PCR-DGGE and pyrosequencing provided a consensus of EM diversity; for example, a high abundance of pyrosequencing reads and DGGE bands corresponded to M. moriokaense, M. colombiense and M. riyadhense. As expected pyrosequencing provided more comprehensive information; additional prevalent species included M. chlorophenolicum, M. neglectum, M. gordonae, M. aemonae. Prevalence of the total Mycobacterium genus in the soil samples ranged from 2.3×107 to 2.7×108 gene targets g−1; slow growers prevalence from 2.9×105 to 1.2×107 cells g−1.
Conclusions: This combined molecular approach enabled an unprecedented qualitative and quantitative assessment of EM across soil samples. Good concordance was found between methods and the bioinformatics analysis was validated by random resampling. Sequences from most pathogenic groups associated with slow growth were identified in extenso in all soils tested with a specific assay, allowing to unmask them from the Mycobacterium whole genus, in which, as minority members, they would have remained undetected
Targeting poly(ADP-ribose) polymerase activity for cancer therapy
Poly(ADP-ribosyl)ation is a ubiquitous protein modification found in mammalian cells that modulates many cellular responses, including DNA repair. The poly(ADP-ribose) polymerase (PARP) family catalyze the formation and addition onto proteins of negatively charged ADP-ribose polymers synthesized from NAD+. The absence of PARP-1 and PARP-2, both of which are activated by DNA damage, results in hypersensitivity to ionizing radiation and alkylating agents. PARP inhibitors that compete with NAD+ at the enzyme’s activity site are effective chemo- and radiopotentiation agents and, in BRCA-deficient tumors, can be used as single-agent therapies acting through the principle of synthetic lethality. Through extensive drug-development programs, third-generation inhibitors have now entered clinical trials and are showing great promise. However, both PARP-1 and PARP-2 are not only involved in DNA repair but also in transcription regulation, chromatin modification, and cellular homeostasis. The impact on these processes of PARP inhibition on long-term therapeutic responses needs to be investigated
Introducing the INSIGNIA project: Environmental monitoring of pesticides use through honey bees
INSIGNIA aims to design and test an innovative, non-invasive, scientifically proven citizen science environmental monitoring protocol for the detection of pesticides via honey bees. It is a pilot project initiated and financed by the European Commission (PP-1-1-2018; EC SANTE). The study is being carried out by a consortium of specialists in honey bees, apiculture, chemistry, molecular biology, statistics, analytics, modelling, extension, social science and citizen science from twelve countries. Honey bee colonies are excellent bio-samplers of biological material such as nectar, pollen and plant pathogens, as well as non-biological material such as pesticides or airborne contamination. Honey bee colonies forage over a circle of about 1 km radius, increasing to several km if required depending on the availability and attractiveness of food. All material collected is concentrated in the hive, and the honey bee colony can provide four main matrices for environmental monitoring: bees, honey, pollen and wax. For pesticides, pollen and wax are the focal matrices. Pollen collected in pollen traps will be sampled every two weeks to record foraging conditions. During the season, most of pollen is consumed within days, so beebread can provide recent, random sampling results. On the other hand wax acts as a passive sampler, building up an archive of pesticides that have entered the hive. Alternative in-hive passive samplers will be tested to replicate wax as a “pesticide-sponge”. Samples will be analysed for the presence of pesticides and the botanical origin of the pollen using an ITS2 DNA metabarcoding approach. Data on pollen and pesticides will be then be combined to obtain information on foraging conditions and pesticide use, together with evaluation of the CORINE database for land use and pesticide legislation to model the exposure risks to honey bees and wild bees. All monitoring steps from sampling through to analysis will be studied and tested in four countries in year 1, and the best practices will then be ring-tested in nine countries in year 2. Information about the course of the project and its results and publications will be available in the INSIGNIA website www.insignia-bee.eu.info:eu-repo/semantics/publishedVersio
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