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Vitamin B12 (cobalamin, Cbl) is required as a cofactor by two human enzymes, 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) and methylmalonyl-CoA mutase (MMUT). Within the body, a vast array of transporters, enzymes and chaperones are required for the generation and delivery of these cofactor forms. How they perform these functions is dictated by the structure and interactions of the proteins involved, the molecular bases of which are only now being elucidated. In this review, we highlight recent insights into human Cbl metabolism and address open questions in the field by employing a protein structure and interactome based perspective. We discuss how three very similar proteins-haptocorrin, intrinsic factor and transcobalamin-exploit slight structural differences and unique ligand receptor interactions to effect selective Cbl absorption and internalisation. We describe recent advances in the understanding of how endocytosed Cbl is transported across the lysosomal membrane and the implications of the recently solved ABCD4 structure. We detail how MMACHC and MMADHC cooperate to modify and target cytosolic Cbl to the client enzymes MTR and MMUT using ingenious modifications to an ancient nitroreductase fold, and how MTR and MMUT link with their accessory enzymes to sustainably harness the supernucleophilic potential of Cbl. Finally, we provide an outlook on how future studies may combine structural and interactome based approaches and incorporate knowledge of post-translational modifications to bring further insights.
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Metilmalonil-CoA Mutasa , Vitamina B 12 , Humanos , Vitamina B 12/metabolismo , Metilmalonil-CoA Mutasa/metabolismo , Transporte Biológico , Chaperonas Moleculares , Transportadoras de Casetes de Unión a ATP/metabolismo , Oxidorreductasas/metabolismoRESUMEN
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is a disease that causes serious problems to the global citrus industry. Matrix-Assisted Laser Desorption/Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry (MS) has been used in human medicine to diagnose various diseases caused by both fungi and bacteria. In agriculture, this technique has potential for the diagnosis of diseases due to the low cost of large-scale analysis and quickness. This study showed that MALDI-TOF MS combined with chemometric analysis was effective for differentiating the macromolecule profile of orange leaves with canker lesions, healthy leaves, and leaves with phytotoxicity symptoms, proving that this technique may be used for the rapid diagnosis of citrus canker.
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Citrus sinensis , Citrus , Xanthomonas , Humanos , Citrus/microbiología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Citrus sinensis/microbiología , Enfermedades de las Plantas/microbiologíaRESUMEN
An endophytic bacterium inhibiting pathogenic bacteria was isolated and the strain was genetically identified as Paenibacillus polymyxa. Biochemical characterization of fermentation broth indicated the presence of peptidic antimicrobial molecules. Liquid-liquid partition resulted in an organic fraction (OF) and an aqueous fraction (AF). OF presented a broad spectrum of activity against a panel of pathogenic bacteria and a fungus whereas the AF was active only against Gram-negative bacteria. AF was sequentially submitted to ion-exchange, desalting and reverse phase (RP) chromatography. A molecule with an RT of 2.45 min exhibited activity against all Gram-negative pathogenic strains tested beside P. mirabilis. The primary structure of the molecule, named AMP-Pp, was determined as Gly-Glu-Hyp-Gly-Ala by N-terminal sequencing. The molecular mass and amino acid sequence were confirmed by MS/MS. With a molecular mass of 463 Da, AMP-Pp is one of the smallest active natural peptides reported, yet. RP chromatography of OF resulted in four peaks. The first three peaks corresponded to known antimicrobials. MS analysis of peak 4 revealed the presence of an ion with m/z 3,376.4 Da, whose proposed molecular formula is C182H321N29O29. The compound, named polycerradin, showed a spectrum of activity against Gram-positive bacteria, Gram-negative bacteria (beside P. mirabilis) and a fungus.
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Antiinfecciosos , Paenibacillus polymyxa , Bacterias Gramnegativas , Bacterias Grampositivas , Espectrometría de Masas en TándemRESUMEN
A comprehensive overview of natural orbitides isolated from Euphorbiaceae species and their most relevant biological activities are presented. Euphorbiaceae is a large and diverse family, which comprises about 300 genera, and is known as an important source of medicines and toxins. Several classes of secondary metabolites have been described for this taxon, however, orbitides have been broadly reported in Jatropha and Croton genera. Additionally, the latex is documented as the main source of orbitides in this family. Based on their structural and functional diversity, orbitides present a large variety of biological activities described as cytotoxicity, antimalarial, antibacterial, antifungal, enzymatic inhibition, and immunosuppressive, although the mechanism of action still needs to be further investigated. In recent years, the discovery of bioactive cyclic peptides from different sources has grown exponentially, making them promising molecules in the search for new drug leads. This review also highlights the attempts made by many researchers to organize the orbitides nomenclature and amino acid numbering, as well the important progress recently achieved in the biosynthetic study area.
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Antiinfecciosos/farmacología , Productos Biológicos/farmacología , Euphorbiaceae/química , Inmunosupresores/farmacología , Péptidos Cíclicos/farmacología , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Antiinfecciosos/química , Antiinfecciosos/aislamiento & purificación , Antifúngicos/química , Antifúngicos/aislamiento & purificación , Antifúngicos/farmacología , Antimaláricos/química , Antimaláricos/aislamiento & purificación , Antimaláricos/farmacología , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Croton/química , Croton/clasificación , Croton/metabolismo , Euphorbiaceae/clasificación , Euphorbiaceae/metabolismo , Inmunosupresores/química , Inmunosupresores/aislamiento & purificación , Jatropha/química , Jatropha/clasificación , Jatropha/metabolismo , Péptidos Cíclicos/química , Péptidos Cíclicos/aislamiento & purificaciónRESUMEN
This study estimated the reference evapotranspiration rate (ETo) for the Itacaiúnas River Watershed (IRW), Eastern Amazonia, and measured the accuracy of eight empirical equations: Penman-Monteith (PM), Priestley-Taylor (PT), Hargreaves and Samani (HS), Camargo (CAM), Thornthwaite (TH), Hamon (HM), Kharrufa (KF) and Turc (TC) using monthly data from 1980 to 2013. In addition, it verifies the regional applicability to the IRW using a for the Marabá-PA station. The methods TC and PM (FAO56) presented the best results, which demonstrate that radiation and higher temperatures are the dominant drivers in the Evapotranspiration process, while relative humidity and wind speed have a much smaller impact. The temporal and spatial variability of ETo for IRW show has strong seasonality, increasing during the dry season and decreasing during the rainy season. The statistical analyses at 1% level of significance, indicates that there is no correlation of the residuals between the dry and rainy seasons, and test of the physical parameters such as mean temperature, solar radiation and relative air humidity explains the variations of ETo.
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Strain SB026T was isolated from Brazilian rainforest soil and its taxonomic position established using data from a polyphasic study. The organism showed a combination of chemotaxonomic and morphological features consistent with its classification in the genus Amycolatopsis and formed a branch in the Amycolatopsis 16S rRNA gene tree together with Amycolatopsis bullii NRRL B-24847T, Amycolatopsis plumensis NRRL B-24324T, Amycolatopsis tolypomycina DSM 44544T and Amycolatopsis vancoresmycina NRRL B-24208T. It was related most closely to A. bullii NRRL B-24847T (99.0 % 16S rRNA gene sequence similarity), but was distinguished from this strain by a low level of DNA-DNA relatedness (~46 %) and discriminatory phenotypic properties. Based on the combined genotypic and phenotypic data, it is proposed that the isolate should be classified in the genus Amycolatopsis as representing a novel species, Amycolatopsis rhabdoformis sp. nov. The type strain is SB026T (â= CBMAI 1694T = CMAA 1285T = NCIMB 14900T).
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Actinomycetales/clasificación , Bosques , Filogenia , Microbiología del Suelo , Actinomycetales/genética , Actinomycetales/aislamiento & purificación , Bacterias Aerobias/genética , Técnicas de Tipificación Bacteriana , Brasil , ADN Bacteriano/genética , Ácidos Grasos/química , Datos de Secuencia Molecular , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Suelo , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
Empirical orthogonal functions (EOF) and composites analysis were employed on pentad data in order to investigate the tropical atmospheric-ocean patterns over the Atlantic Ocean and the spatial-temporal characteristics of the rainfall in eastern Amazon during the peak of the rainy season (February to April). The EOF results evidenced that the Intertropical Convergence Zone (ITCZ) is the main rainfall-producing system in eastern Amazon during the rainy season. Conditions associated with the southward SST gradient in the intertropical Atlantic formed the dynamic patterns that favored the position of the ITCZ to south of the equator, thus explaining the predominance of positive precipitation anomalies in eastern Amazon, especially in the state of Maranhão and northeastern Pará during the February and April months.
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Lluvia , Estaciones del Año , Océano Atlántico , Brasil , América del Sur , Factores de Tiempo , Clima TropicalRESUMEN
Cystathionine beta-synthase (CBS) is an essential metabolic enzyme across all domains of life for the production of glutathione, cysteine, and hydrogen sulfide. Appended to the conserved catalytic domain of human CBS is a regulatory domain that modulates activity by S-adenosyl-L-methionine (SAM) and promotes oligomerisation. Here we show using cryo-electron microscopy that full-length human CBS in the basal and SAM-bound activated states polymerises as filaments mediated by a conserved regulatory domain loop. In the basal state, CBS regulatory domains sterically block the catalytic domain active site, resulting in a low-activity filament with three CBS dimers per turn. This steric block is removed when in the activated state, one SAM molecule binds to the regulatory domain, forming a high-activity filament with two CBS dimers per turn. These large conformational changes result in a central filament of SAM-stabilised regulatory domains at the core, decorated with highly flexible catalytic domains. Polymerisation stabilises CBS and reduces thermal denaturation. In PC-3 cells, we observed nutrient-responsive CBS filamentation that disassembles when methionine is depleted and reversed in the presence of SAM. Together our findings extend our understanding of CBS enzyme regulation, and open new avenues for investigating the pathogenic mechanism and therapeutic opportunities for CBS-associated disorders.
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Cistationina betasintasa , Metionina , Humanos , Cistationina betasintasa/metabolismo , Microscopía por Crioelectrón , S-Adenosilmetionina/metabolismo , Dominio CatalíticoRESUMEN
Levetiracetam (LEV) is an anticonvulsant for epilepsy. The toxic effects of this medication in tissues have been associated with redox state imbalance, which can lead to salivary gland dysfunction. Therefore, the current work investigated the effects of LEV on the biochemical, functional, and redox parameters of the parotid and submandibular glands in rats. For this, male Wistar rats (Rattus norvegicus albinus) were randomly divided into 3 groups (n = 10/group): Control (0.9% saline solution), LEV100 (100 mg/kg), and LEV300 (300 mg/kg). After 21 consecutive days of intragastric gavage treatments, pilocarpine stimulated saliva secretion was collected for salivary biochemical analysis. The extracted salivary glands were utilized for histomorphometry and redox state analyses. Our results showed that LEV300 increased plasma hepatotoxicity markers and reduced salivary amylase activity and the acinar surface area of the parotid gland. Total oxidant capacity and oxidative damage to lipids and proteins were higher in the parotid gland, while total antioxidant capacity and uric acid levels were reduced in the submandibular gland of the LEV100 group compared to Control. On the other hand, total oxidant capacity, oxidative damage to lipids and proteins, total antioxidant capacity, and uric acid levels were lower in both salivary glands of the LEV300 group compared to Control. Superoxide dismutase and glutathione peroxidase activities were lower in the salivary glands of treated animals compared to Control. In conclusion our data suggest that treatment with LEV represents a potentially toxic agent, that contributes to drug-induced salivary gland dysfunction.
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Antioxidantes , Ácido Úrico , Ratas , Masculino , Animales , Ratas Wistar , Antioxidantes/farmacología , Levetiracetam/toxicidad , Levetiracetam/metabolismo , Ácido Úrico/metabolismo , Ácido Úrico/farmacología , Glándulas Salivales/metabolismo , Oxidación-Reducción , Proteínas/metabolismo , Oxidantes/metabolismo , LípidosRESUMEN
OBJECTIVE: To investigate the effects of the anticonvulsant valproic acid (VPA) on salivary glands in male rat using biochemical, functional, histomorphometric, and redox state parameters. MATERIALS AND METHODS: Twenty-four male Wistar rats were randomly distributed into three groups (n = 8 per group): Control (0.9% saline solution), VPA100 (100 mg/kg), and VPA400 (400 mg/kg). After 21 consecutive days of treatment with by intragastric gavage. Pilocarpine-induced saliva was collected to determine salivary flow rate, pH, buffering capacity, and biochemical composition. Analyses of histomorphometric parameters and redox balance markers were performed on the parotid and submandibular glands. RESULTS: Salivary flow rate, pH, buffering capacity, total protein, potassium, sodium, and chloride were similar between groups. However, phosphate and calcium were reduced in VPA400, while amylase was increased in both VPA100 and VPA400. We did not detect significant differences in the areas of acini, ducts, and connective tissue in the salivary glands between the groups. There were no significant changes in the redox status of the submandibular glands. In turn, in the parotid glands we detected reduced total oxidizing capacity and lipid peroxidation, measured as thiobarbituric acid reactive substances (TBARs) and higher uric acid concentration in both the VPA100 and VPA400 groups, and increased superoxide dismutase (SOD) in the VPA400 group. CONCLUSION: Chronic treatment with VPA modified the salivary biochemical composition and caused disruption in the redox state of the parotid gland in rats.
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Anticonvulsivantes , Ácido Valproico , Ratas , Masculino , Animales , Anticonvulsivantes/farmacología , Ácido Valproico/farmacología , Ácido Valproico/análisis , Ácido Valproico/metabolismo , Ratas Wistar , Glándulas Salivales/metabolismo , Saliva/química , Glándula Parótida/metabolismo , Glándula Submandibular/metabolismo , Oxidación-ReducciónRESUMEN
In this work, a painting suspected of counterfeiting was analyzed using the synchrotron-based scanning macro X-ray fluorescence (MA-XRF) technique. The canvas has erasures including a signature erasure; however, some visible numbers indicate that the artwork may be from the 17th century. Through the studies' elemental maps, Cl-K and Ca-K were observed, which allowed us to reconstruct the signature present in the painting. Elemental maps of Ba-K, Ti-K, Fe-K, Zn-K, and Pb-K were also obtained from the painting, which made possible to visualize how the pigments based on these elements were used in the creative composition of the painting. In addition to the signature region, a region of the painting with dimensions of approximately 120 mm × 120 mm was investigated by synchrotron radiation induced MA-XRF, while keeping a high spatial resolution and elemental sensitivity. The measurements were carried out at the D09B micro-XRF beamline of the Brazilian Synchrotron Light Laboratory (LNLS), part of the Brazilian Center of Research in Energy and Materials, in Campinas Brazil. The painting was also investigated by SEM-EDS, and FTIR techniques. Those results, in addition to the supporting elemental maps, allowed additional information to be obtained, such as the binders used on the painting.
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Loxoscelism is a recognized public health problem in Brazil, but the venom from Loxosceles similis, which is widespread in Brazil due to its adaptability to the urban environment, remains poorly characterized. Loxtox is a family of phospholipase D enzymes (PLDs), which are the major components of Loxosceles venom and are responsible for the clinical effects of loxoscelism. Loxtox toxins correspond to 15% of L. similis venom gland transcripts, but the Loxtox family of L. similis has yet to be fully described. In this study, we cloned and functionally characterized recLoxtox s1A and recLoxtox s11A. These recombinant toxins exhibited different in vitro activities depending on pH, and recLoxtox s1A had more intense effects on rabbit skin than did recLoxtox s11A in vivo. Both recombinant toxins were used in immunization protocols, and mapping of their epitopes revealed different immunological reactions for the produced immune serums. Additionally, polyclonal antibodies raised against recLoxtox s1A had greater capacity to significantly reduce the in vitro and in vivo effects of L. similis venom. In summary, we obtained and characterized two novel Loxtox isoforms from L. similis venom, which may be valuable biotechnological and immunological tools against loxoscelism.
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Hidrolasas Diéster Fosfóricas/metabolismo , Venenos de Araña/metabolismo , Arañas/metabolismo , Animales , Clonación Molecular , Epítopos/química , Femenino , Concentración de Iones de Hidrógeno , Sueros Inmunes/inmunología , Pruebas de Neutralización , Fosfolipasa D/metabolismo , Hidrolasas Diéster Fosfóricas/genética , Isoformas de Proteínas , Conejos , Proteínas Recombinantes/metabolismo , Piel/efectos de los fármacos , Esfingomielina Fosfodiesterasa/metabolismo , Venenos de Araña/genéticaRESUMEN
The dynamics of dengue transmission are multifactorial and involve socioeconomic, ecological, and environmental aspects, the latter being closely related to local climatic conditions that affect the vector's reproductive cycle. Climate depends in turn on tropical oceanic mechanisms such as phases of El Niño/La Niña over the Pacific. The study contributes to this discussion and reports on the correlations between the Multivariate ENSO Index (MEI) in the Pacific and the number of reported dengue cases in seven state capitals in the Brazilian Amazon from 2001 to 2012. The study also analyzes the seasonality pattern (quarterly mean values) in dengue cases throughout the region. Evidence that El Niño/La Niña causes a decrease versus increase in the local rainfall pattern is consistent with the lower versus higher number of reported dengue cases in most of the state capitals in the Amazon, a result proven by the statistically significant negative correlations seen in Manaus (Amazonas), São Luís (Maranhão), Belém (Pará) and Palmas (Tocantins). The 12-years means (2001-2012) revealed the presence of pronounced seasonality in dengue incidence in the majority of the state capitals, with sharp peaks from January to March [Rio Branco (Acre), Manaus, Belém and Palmas] and from April to June (São Luís), corresponding to 50-70% of the annual total. State capitals farther north [Boa Vista (Roraima) and Macapá (Amapá)] showed dengue reporting in all quarters of the year, with no pronounced seasonality.
A dinâmica de transmissão da dengue é multifatorial e envolve aspectos socioeconômicos, ecológicos e ambientais, sendo este último intimamente relacionado às condições climáticas locais que interferem no ciclo reprodutivo dos vetores da doença. Por sua vez, o clima é dependente dos mecanismos oceânicos tropicais, a exemplo das fases de El Niño/La Niña sobre o Pacífico. O presente trabalho contribui com esta temática e reporta as correlações entre o índice MEI (Multivariate ENOS Index) do Pacífico e o número de casos notificados de dengue em sete capitais da Amazônia brasileira, no período de 2001 a 2012. Além disso, investiga-se o padrão de sazonalidade (médias trimestrais) dos casos de dengue ao longo da região. As evidências de que o fenômeno El Niño/La Niña provoca redução/aumento no padrão pluviométrico local é consistente com o número menor/maior de casos notificados de dengue na maior parte das capitais amazônicas, cujo resultado foi comprovado pelas correlações negativas estatisticamente significantes encontradas para Manaus (Amazonas), São Luís (Maranhão), Belém (Pará) e Palmas (Tocantins). As médias dos 12 anos (2001/2012) revelaram a presença de sazonalidade pronunciada na incidência de dengue na maioria das capitais, com picos acentuados de janeiro a março [Rio Branco (Acre), Manaus, Belém e Palmas] e de abril a junho (São Luís), correspondendo em torno de 50% a 70% do total anual. As localidades mais ao norte [Boa Vista (Roraima) e Macapá (Amapá)] revelaram registro da dengue ao longo de todos os trimestres do ano, não apresentando sazonalidade acentuada.
La dinámica de transmisión del dengue es multifactorial e implica aspectos socioeconómicos, ecológicos y ambientales, estando estos últimos íntimamente relacionados con las condiciones climáticas locales que interfieren en el ciclo reproductivo de los vectores de la enfermedad. A su vez, el clima depende de los mecanismos oceánicos tropicales, como por ejemplo las fases de El Niño/La Niña sobre el Pacífico. El presente trabajo contribuye a esta temática e informa sobre las correlaciones entre el índice MEI (Multivariate ENOS Index) del Pacífico y el número de casos notificados de dengue en siete capitales de la Amazonia brasileña durante el período de 2001 a 2012. Además, se investiga el patrón de estacionalidad (medias trimestrales) de los casos de dengue a lo largo de la región. Las evidencias de que el fenómeno El Niño/La Niña provoca reducción/aumento en el patrón pluviométrico local es consistente con el número menor/mayor de casos notificados de dengue en la mayor parte de las capitales amazónicas, cuyo resultado se comprobó por las correlaciones negativas estadísticamente significativas encontradas en Manaus (Amazonas), São Luís (Maranhão), Belém (Pará) y Palmas (Tocantins). Las medias de los doce años (2001/2012) revelaron la presencia de estacionalidad pronunciada en la incidencia de dengue en la mayoría de las capitales, con picos acentuados de enero a marzo [Rio Branco (Acre), Manaus, Belém y Palmas] y de abril a junio (São Luís), correspondiendo en torno del 50 al 70% del total anual. Las localidades más al norte [Boa Vista (Roraima) y Macapá (Amapá)] revelaron registro del dengue a lo largo de todos los trimestres del año, no presentando una estacionalidad acentuada.
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Dengue/epidemiología , El Niño Oscilación del Sur/efectos adversos , Animales , Brasil/epidemiología , Dengue/transmisión , Vectores de Enfermedades , Humanos , Incidencia , Estaciones del AñoRESUMEN
Abstract Streptococcus agalactiae (group B Streptococcus, GBS) remains one major neonatal pathogen, being maternal colonization a risk factor for infection development. Despite effective, the usage of antibiotics to prevent neonatal infections has limitations. The bacterial polysaccharide capsule is a virulence determinant, a target for vaccine directed to pregnant women, and also the most useful epidemiological marker of GBS infections. Capsular polysaccharides are diverse and disease severity varies according to the expressed type. Here, capsular typing of 124 GBS isolates recovered from pregnant women was determined by a multiplex PCR-based method. The most frequent types were Ia (33.0%), II (25.8%) and V (21.8%). Other types found were Ib (8.9%), III (8.9%) and IV (1.6%). While type Ia was prevalent during the whole period (2002-2018), fluctuations in distribution of other types, specially V, were observed over time. Capsular type III, traditionally associated with severe neonatal infections, was poorly detected. Distribution of maternal GBS capsular types in the metropolitan area of Rio de Janeiro, with prevalence of Ia and II, is quite different from other parts of the world. The knowledge about GBS capsular type distribution is essential to predict the theoretical impact of developing capsule-based vaccines in the local population.
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BACKGROUND: The rapid increase in the aged population has resulted in a growing number of cases of chronic diseases. This increase is an important demographic change that low- and middle-income countries have to face and poses a new challenge to health services. One of the first steps to formulate public policies is to understand the reality of each country's aging population. This study describes the prevalence of anemia, hypertension and diabetes and the overall health status in pre-elderly and elderly subjects enrolled in two primary health care clinics, Eldorado and Piraporinha, in the city of Diadema, São Paulo. METHOD: A cross-sectional study was conducted with 373 participants. Clinical data were collected from patient charts and the degree of disability and common mental disorders, as well as demographic data were obtained by interviews. RESULTS: The prevalence of anemia was approximately 11% and hypertension was 70% and 81% in Eldorado and Piraporinha, respectively. The frequency of diabetes was 52% in Eldorado and 30% in Piraporinha. The subjects of both health care clinics reported having difficulties in some of their daily physical and instrumental activities, with physical symptoms and emotional disorders. CONCLUSION: Anemia, hypertension and diabetes are prevalent in the studied population, and patients showed degrees of dependency and impaired health status.
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ABSTRACT The Hermanella complex is a well-established monophyletic group of Hagenulinae mayflies, but the phylogenetic relationships among its members are still being discussed. In order to fill some gaps in the taxonomy of this group we describe, for the first time, the eggs of eight species of this complex (Hermanella amere, Hermanella mazama, Hydromastodon sallesi, Hydrosmilodon gilliesae, Hydrosmilodon plagatus, Leentvaaria palpalis, Paramaka incognita, Paramaka sp.) using scanning electron microscopy, including some important members whose generic allocation have been questioned. The egg morphology in these eight species of Hermanella complex and their similarities with other species of the complex are discussed.
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In this study, twenty samples of clay smoking pipes excavated in an 18km(2) area between the Macacu and Caceribu rivers, in the municipality of Itaboraí, Rio de Janeiro, Brazil were analyzed by FT-IR technique. The samples, excavated in different archeological sites of the region, are dated between the seventeenth and the nineteenth centuries and are part of the material culture left by Africans and African descendants that lived in the complex. FT-IR analyses and complementary SEM-EDS studies showed that the clay paste used in the manufacture of smoking pipes, mostly handcrafted, is composed of quartz, feldspar, phyllosilicates and iron oxides. Multivariate statistical tests (PCA) were applied to FT-IR data to assess the interactions between the archeological sites. The results indicated that one archeological site - Macacu IV - is greatly related to the other sites. The results obtained have helped archeologists and anthropologists in better understanding the manufacturing process employed in ancient ceramic artifacts produced during the period of colonial Brazil.
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In this study, samples were taken from the sculpture of Our Lady of Sorrows and analyzed by Raman spectroscopy and FT-IR. This sculpture has been dated to the early eighteenth century. Samples were also examined using optical microscopy and Energy Dispersive Spectroscopy (EDS). Based on chemical analysis, the pigments vermilion [HgS], massicot [PbO] and azurite [Cu3(CO3)2(OH)2]were found in the sculpture polychrome. The results indicate that the green polychrome of the sculpture's mantle comes from the blending of massicot and azurite. Because the literature reports that the mantle of the Our Lady of Sorrows sculpture is blue, the mixing of these pigments results from a production error. The results also indicate the presence of Au in the sculpture, which indicates the originality of the piece. The results from this study helped restorers to choose the appropriate procedures for intervening in the sculpture and contributed to the knowledge about the manufacturing process of Brazilian baroque sculptures.
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In this work we have identified, using mass spectrometry, two laccases produced by Leucoagaricus gongylophorus. One of them, Lac1Lg, was isolated, purified and characterized. Lac1Lg, a monomeric enzyme, was studied using ABTS and syringaldazine substrates. Lac1Lg presented kcat/Km almost threefold higher for syringaldazine than for ABTS, showing a higher catalytic efficiency of Lac1Lg for syringaldazine. The interference of several metal ions and substances in the laccase activity were evaluated. Lac1Lg did not absorb at 600 nm, which is a characteristic of so-called yellow laccases. Lac1Lg also was able to oxidize non-phenolic substrate (anthracene) in the absence of an exogenous mediator, showing that the enzyme has potential to explore in biotechnological processes. Our Lac1Lg three-dimensional molecular model, constructed using homology modeling, showed that the Lac1Lg catalytic site is very closed to blue laccases.
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We assessed the species diversity among 45 strains of Clonostachys from different substrates and localities in Brazil using molecular phylogenetics, and compared the results with the phenotypic classification of strains obtained from matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Phylogenetic analyses were based on beta tubulin (Tub), ITS-LSU rDNA, and a combined Tub-ITS DNA dataset. MALDI-TOF MS analyses were performed using intact conidia and conidiophores of strains cultivated on oatmeal agar and 4% malt extract agar. Six known species were identified: Clonostachys byssicola, Clonostachys candelabrum, Clonostachys pseudochroleuca, Clonostachys rhizophaga, Clonostachys rogersoniana, and Clonostachys rosea. Two clades and two singleton lineages did not correspond to known species represented in the reference DNA dataset and were identified as Clonostachys sp. 1-4. Multivariate cluster analyses of MALDI-TOF MS data classified the strains into eight clusters and three singletons, corresponding to the ten identified species plus one additional cluster containing two strains of C. rogersoniana that split from the other co-specific strains. The consistent results of MALDI-TOF MS supported the identification of strains assigned to C. byssicola and C. pseudochroleuca, which did not form well supported clades in all phylogenetic analyses, but formed distinct clusters in the MALDI-TOF dendrograms.