Purification and Preliminary Characterization of Tetraheme Cytochrome and Adenylylsulf te Reductase from the Peptidolytic Sulfate-Reducing Bacterium Desulfovibrio aminophilus DSM 12254

Bioinorganic Chemistry and Applications Volume 3 (2005), Issue 1-2, Pages 81-91Two proteins were purified and preliminarily characterized from the soluble extract of cells (310 g, wet weight) of the aminolytic and peptidolytic sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254. The iron-sulfur flavoenzyme adenylylsulfate (adenosine 5"-phosphosulfate, APS)reductase, a key enzyme in the microbial dissimilatory sulfate reduction, has been purified in three chromatographic steps(DEAE-Biogel A, Source 15, and Superdex 200 columns). It contains two different subunits with molecular masses of 75 and 18 kDa. The fraction after the last purification step had a purity index (A278 ,m/A388 nm) of 5.34, which was used for further EPR spectroscopic studies. The D. aminophilus APS reductase is very similar to the homologous enzymes isolated from D. gigas and D. desulfuricans ATCC 27774. A tetraheme cytochrome c3 (His-heme iron-His) has been purified in three chromatographic steps (DEAE- Biogel A,Source 15, and Biogel-HTP columns) and preliminarily characterized. It has a purity index ([A.s.s3 nm" A570 nm]rcd/m280nm ox) of 2.9 and a molecular mass of around 15 kDa, and its spectroscopic characterization(NMR and EPR) has been carried out. This hemoprotein presents similarities with the tetraheme cytochrome c3 from Desulfomicrobium (Des.) norvegicurn (NMR spectra, and N-terminal amino acid sequence)

Purification and Preliminary Characterization of Tetraheme Cytochrome c3 and Adenylylsulfate Reductase from the Peptidolytic Sulfate-Reducing Bacterium Desulfovibrio aminophilus DSM 12254

Two proteins were purified and preliminarily characterized from the soluble extract of cells (310 g, wet weight) of the aminolytic and peptidolytic sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254. The iron-sulfur flavoenzyme adenylylsulfate (adenosine 5'-phosphosulfate, APS) reductase, a key enzyme in the microbial dissimilatory sulfate reduction, has been purified in three chromatographic steps (DEAE-Biogel A, Source 15, and Superdex 200 columns). It contains two different subunits with molecular masses of 75 and 18 kDa. The fraction after the last purification step had a purity index (A278nm / A388nm) of 5.34, which was used for further EPR spectroscopic studies. The D. aminophilus APS reductase is very similar to the homologous enzymes isolated from D. gigas and D. desulfuricans ATCC 27774. A tetraheme cytochrome c3 (His-heme iron-His) has been purified in three chromatographic steps (DEAE- Biogel A, Source 15, and Biogel-HTP columns) and preliminarily characterized. It has a purity index ([A553nm - A570nm]red / A280nm) of 2.9 and a molecular mass of around 15 kDa, and its spectroscopic characterization (NMR and EPR) has been carried out. This hemoprotein presents similarities with the tetraheme cytochrome c3 from Desulfomicrobium (Des.) norvegicum (NMR spectra, and N-terminal amino acid sequence)

Hoja Geológica 2969-IV, Villa Unión

La Hoja Geológica 2969-IV Villa Unión abarca parte de la región noroccidental de la Provincia de La Rioja y el sector occidentalde la Hoja comprende una porción del noreste de la provincia de San Juan. Se extiende entre los paralelos 29º y 30º de latitud sur yentre los meridianos 67º 30 y 69º de longitud oeste, cubriendo una superfi cie aproximada de 18.000 km2. La Hoja toma el nombrede la localidad más importante del oeste riojano, Villa Unión. Otra localidad importante del mismo sector es Villa Castelli, como laanterior, a orillas del río Vinchina-Bermejo, en el límite norte de la Hoja. La localidad más occidental de la Hoja es Guandacol enla depresión tectónica recorrida por el río homónimo. Finalmente al naciente de la sierra de Famatina y dentro del área de la Hojase ubican, de norte a sur las localidades de: Las Higueritas, Chilecito, Sañogasta y Vichigasta. La Hoja Villa Unión incluye partede tres provincias geológicas argentinas, de este a oeste: Sistema de Famatina, Sierras Pampeanas occidentales y Precordillera.En la Hoja Villa Unión afl oran basamentos metamórfi cos muy distintos como consecuencia de las colisiones y acreciones dediferentes terrenos (Famatina, Cuyania y Chilenia) ocurridas durante el Proterozoico superior y el Paleozoico inferior. Los terrenosmetamórfi cos del Sistema de Famatina son de muy bajo a bajo grado, mientras que los terrenos metamórfi cos de Sierras PampeanasOccidentales son de grado medio a alto. El basamento correspondiente a Sierras Pampeanas Occidentales, afl orante en la Hoja VillaUnión, conforma los bloques serranos de Umango, Maz, Espinal y Las Ramaditas, elevados como consecuencia de la tectónicaterciaria-cuaternaria. En ellos las litologías predominantes son: gneises, esquistos, calizas, anfi bolitas y granitoides. En la sierra deFamatina el basamento esta representado por la Formación Negro Peinado, compuesta por leptometamorfi tas. Sobre ellas se apoyanen discordancia sedimentitas ordovícicas de la Formación Suri que se interdigitan con rocas volcánicas. Estas rocas están intruidaspor una secuencia de cuerpos plutónicos calcoalcalinos de la Formación Ñuñorco, caracterizada por gabros, tonalitas, granodioritas ygranitos, con un clímax de actividad magmática en el Ordovícico medio a superior. Ellas representan un arco magmático desarrolladoen un margen continental activo. Cuyania es un terreno compuesto, con suturas internas representadas por una faja ofi olítica de edadGrenville. Los terrenos amalgamados (Precordillera y Pie de Palo) para formar Cuyania serían posibles arcos de islas intraoceánicosrepresentados por anfi bolitas y gneises. Sobre Cuyania se desarrolló una plataforma calcárea de edad cambro-ordovícica. Las rocasmás antiguas de esta secuencia afloran al noroeste de Guandacol, estan constituidas por depósitos continentales rojos y evaporitasde edad cámbrica inferior (Formación Cerro Totora). En discordancia se apoyan los depósitos de plataforma carbonática (FormaciónSan Juan), además de secuencias ordovícicas clásticas (Formación Guandacol, Formación Yerba Loca) y fi nalmente secuenciasclásticas con niveles conglomerádicos (Grupo Trapiche) del Ordovícico superior.Fil: Fauque, Luis Enrique. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Limarino, Carlos Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Vujovich, G.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Cegarra, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Yamín, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Tedesco, A.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Ecosteguy, L.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Cardó, R.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Díaz, I.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Franchi, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; ArgentinaFil: Etcheverría, M.. Secretaría de Industria y Minería. Servicio Geológico Minero Argentino; Argentin

The Intensity of IUGR-Induced Transcriptome Deregulations Is Inversely Correlated with the Onset of Organ Function in a Rat Model

A low-protein diet applied during pregnancy in the rat results in intrauterine growth restricted (IUGR) fetuses. In humans, IUGR is associated with increased perinatal morbidity, higher incidence of neuro-developmental defects and increased risk of adult metabolic anomalies, such as diabetes and cardiovascular disease. Development and function of many organs are affected by environmental conditions such as those inducing fetal and early postnatal growth restriction. This phenomenon, termed “fetal programming” has been studied unconnectedly in some organs, but very few studies (if any) have investigated at the same time several organs, on a more comparative basis. However, it is quite probable that IUGR affects differentially most organ systems, with possible persistent changes in gene expression. In this study we address transcriptional alterations induced by IUGR in a multi-organ perspective, by systematic analysis of 20-days rat fetuses. We show that (1) expressional alterations are apparently stronger in organs functioning late in foetal or postnatal life than in organs that are functioning early (2) hierarchical classification of the deregulations put together kidney and placenta in one cluster, liver, lungs and heart in another; (3) the epigenetic machinery is set up especially in the placenta, while its alterations are rather mild in other organs; (4) the genes appear deregulated in chromosome clusters; (5) the altered expression cascades varies from organ to organ, with noticeably a very significant modification of the complement and coagulation cascades in the kidney; (6) we found a significant increase in TF binding site for HNF4 proteins specifically for liver genes that are down-regulated in IUGR, suggesting that this decrease is achieved through the action of HNF transcription factors, that are themselves transcriptionnally induced in the liver by IUGR (x 1.84 fold). Altogether, our study suggests that a combination of tissue-specific mechanisms contributes to bring about tissue-driven modifications of gene cascades. The question of these cascades being activated to adapt the organ to harsh environmental condition, or as an endpoint consequence is still raised

Petri Net computational modelling of Langerhans cell Interferon Regulatory Factor Network predicts their role in T cell activation

Langerhans cells (LCs) are able to orchestrate adaptive immune responses in the skin by interpreting the microenvironmental context in which they encounter foreign substances, but the regulatory basis for this has not been established. Utilising systems immunology approaches combining in silico modelling of a reconstructed gene regulatory network (GRN) with in vitro validation of the predictions, we sought to determine the mechanisms of regulation of immune responses in human primary LCs. The key role of Interferon regulatory factors (IRFs) as controllers of the human Langerhans cell response to epidermal cytokines was revealed by whole transcriptome analysis. Applying Boolean logic we assembled a Petri net-based model of the IRF-GRN which provides molecular pathway predictions for the induction of different transcriptional programmes in LCs. In silico simulations performed after model parameterisation with transcription factor expression values predicted that human LC activation of antigen-specific CD8 T cells would be differentially regulated by epidermal cytokine induction of specific IRF-controlled pathways. This was confirmed by in vitro measurement of IFN-g production by activated T cells. As a proof of concept, this approach shows that stochastic modelling of a specific immune networks renders transcriptome data valuable for the prediction of functional outcomes of immune responses

The exchange activities of [Fe] hydrogenase (iron–sulfur-cluster-free hydrogenase) from methanogenic archaea in comparison with the exchange activities of [FeFe] and [NiFe] hydrogenases

[Fe] hydrogenase (iron–sulfur-cluster-free hydrogenase) catalyzes the reversible reduction of methenyltetrahydromethanopterin (methenyl-H4MPT+) with H2 to methylene-H4MPT, a reaction involved in methanogenesis from H2 and CO2 in many methanogenic archaea. The enzyme harbors an iron-containing cofactor, in which a low-spin iron is complexed by a pyridone, two CO and a cysteine sulfur. [Fe] hydrogenase is thus similar to [NiFe] and [FeFe] hydrogenases, in which a low-spin iron carbonyl complex, albeit in a dinuclear metal center, is also involved in H2 activation. Like the [NiFe] and [FeFe] hydrogenases, [Fe] hydrogenase catalyzes an active exchange of H2 with protons of water; however, this activity is dependent on the presence of the hydride-accepting methenyl-H4MPT+. In its absence the exchange activity is only 0.01% of that in its presence. The residual activity has been attributed to the presence of traces of methenyl-H4MPT+ in the enzyme preparations, but it could also reflect a weak binding of H2 to the iron in the absence of methenyl-H4MPT+. To test this we reinvestigated the exchange activity with [Fe] hydrogenase reconstituted from apoprotein heterologously produced in Escherichia coli and highly purified iron-containing cofactor and found that in the absence of added methenyl-H4MPT+ the exchange activity was below the detection limit of the tritium method employed (0.1 nmol min−1 mg−1). The finding reiterates that for H2 activation by [Fe] hydrogenase the presence of the hydride-accepting methenyl-H4MPT+ is essentially required. This differentiates [Fe] hydrogenase from [FeFe] and [NiFe] hydrogenases, which actively catalyze H2/H2O exchange in the absence of exogenous electron acceptors

Sex- and Diet-Specific Changes of Imprinted Gene Expression and DNA Methylation in Mouse Placenta under a High-Fat Diet

Changes in imprinted gene dosage in the placenta may compromise the prenatal control of nutritional resources. Indeed monoallelic behaviour and sensitivity to changes in regional epigenetic state render imprinted genes both vulnerable and adaptable

Expert consensus document: Clinical and molecular diagnosis, screening and management of Beckwith-Wiedemann syndrome: an international consensus statement.

Beckwith-Wiedemann syndrome (BWS), a human genomic imprinting disorder, is characterized by phenotypic variability that might include overgrowth, macroglossia, abdominal wall defects, neonatal hypoglycaemia, lateralized overgrowth and predisposition to embryonal tumours. Delineation of the molecular defects within the imprinted 11p15.5 region can predict familial recurrence risks and the risk (and type) of embryonal tumour. Despite recent advances in knowledge, there is marked heterogeneity in clinical diagnostic criteria and care. As detailed in this Consensus Statement, an international consensus group agreed upon 72 recommendations for the clinical and molecular diagnosis and management of BWS, including comprehensive protocols for the molecular investigation, care and treatment of patients from the prenatal period to adulthood. The consensus recommendations apply to patients with Beckwith-Wiedemann spectrum (BWSp), covering classical BWS without a molecular diagnosis and BWS-related phenotypes with an 11p15.5 molecular anomaly. Although the consensus group recommends a tumour surveillance programme targeted by molecular subgroups, surveillance might differ according to the local health-care system (for example, in the United States), and the results of targeted and universal surveillance should be evaluated prospectively. International collaboration, including a prospective audit of the results of implementing these consensus recommendations, is required to expand the evidence base for the design of optimum care pathways