Biochemical Characterization and Low-Resolution SAXS Molecular Envelope of GH1 ß-Glycosidase from Saccharophagus degradans.

The marine bacteria Saccharophagus degradans (also known as Microbulbifer degradans), are rod-shaped and gram-negative motile γ-proteobacteria, capable of both degrading a variety of complex polysaccharides and fermenting monosaccharides into ethanol. In order to obtain insights into structure-function relationships of the enzymes, involved in these biochemical processes, we characterized a S. degradans ß-glycosidase from glycoside hydrolase family 1 (SdBgl1B). SdBgl1B has the optimum pH of 6.0 and a melting temperature T m of approximately 50 °C. The enzyme has high specificity toward short D-glucose saccharides with ß-linkages with the following preferences ß-1,3 > ß-1,4 â‰« ß-1,6. The enzyme kinetic parameters, obtained using artificial substrates p-ß-NPGlu and p-ß-NPFuc and also the disaccharides cellobiose, gentiobiose and laminaribiose, revealed SdBgl1B preference for p-ß-NPGlu and laminaribiose, which indicates its affinity for glucose and also preference for ß-1,3 linkages. To better understand structural basis of the enzyme activity its 3D model was built and analysed. The 3D model fits well into the experimentally retrieved low-resolution SAXS-based envelope of the enzyme, confirming monomeric state of SdBgl1B in solution.

Purification, and biochemical and biophysical characterization of cellobiohydrolase I from Trichoderma harzianum IOC 3844.

Because of its elevated cellulolytic activity, the filamentous fungus Trichoderma harzianum has a considerable potential in biomass hydrolysis applications. Trichoderma harzianum cellobiohydrolase I (ThCBHI), an exoglucanase, is an important enzyme in the process of cellulose degradation. Here, we report an easy single-step ion-exchange chromatographic method for purification of ThCBHI and its initial biophysical and biochemical characterization. The ThCBHI produced by induction with microcrystalline cellulose under submerged fermentation was purified on DEAE-Sephadex A-50 media and its identity was confirmed by mass spectrometry. The ThCBHI biochemical characterization showed that the protein has a molecular mass of 66 kDa and pI of 5.23. As confirmed by smallangle X-ray scattering (SAXS), both full-length ThCBHI and its catalytic core domain (CCD) obtained by digestion with papain are monomeric in solution. Secondary structure analysis of ThCBHI by circular dichroism revealed alpha- helices and beta-strands contents in the 28% and 38% range, respectively. The intrinsic fluorescence emission maximum of 337 nm was accounted for as different degrees of exposure of ThCBHI tryptophan residues to water. Moreover, ThCBHI displayed maximum activity at pH 5.0 and temperature of 50 degrees C with specific activities against Avicel and p-nitrophenyl-ß-D-cellobioside of 1.25 U/mg and 1.53 U/mg, respectively.

Condições de vida e saúde da população idosa do município de Guaramiranga-CE / Life and health conditions of the old population of the Municipality of Guaramiranga-CE

Objetivo: descrever condições de vida e saúde dos idosos do Município de Guaramiranga, Ceará. Metodologia: estudo seccional de base populacional, com instrumento de coleta de dados adaptado do Projeto SABE; análise descritiva mediante distribuições de frequência, com emprego do teste qui-quadrado para verificar presença de associações. Resultados: população de estudo constituída por 438 idosos, com predomínio de mulheres na faixa etária de 60-69 anos e escolaridade baixa; idade, presença de doença crônica e prática de atividade física mostraram associação com saúde auto-referida; a prevalência de deficiência visual foi de 73,9 por cento, enquanto a auditiva foi de 29,1 por cento, e 31,1 por cento relataram problemas articulares; a idade mostrou associação com dificuldades na realização das atividades de vida diária. Conclusão: o estudo traça um perfil bastante aproximado das condições de vida e saúde da população idosa de Guaramiranga e pode contribuir para o desenvolvimento de políticas públicas municipais voltadas a esse grupo.

Objective: to describe the living and health conditions of the elder population of the municipality of Guaramiranga,State of Ceará, Brazil. Methodology: a cross-sectional population-based study with data collection tool adapted fromthe SABE Project; descriptive analysis through frequency distributions, and the chi-square test to verify the presenceof associations. Results: the study population consisted of 438 elderly people, mostly women, aged between 60 to 69 years, and with low education; age, presence of chronic disease, and physical activity were associated with self-reported health; the prevalence of visual impairment was of 73.9 per cent, while that of hearing impairment was of 29.1 per cent, and 31.1 per cent reported joint problems; age was associated with difficulties in performing daily living activities. Conclusion: the study draws fairly approximate profile of the life and health conditions of the elderly population of Guaramiranga and may contribute to the development of municipal public policies aimed at this group.

Distrofia muscular de Duchenne: análise eletrocardiográfica de 131 pacientes / Duchenne muscular dystrophy: electrocardiographic analysis of 131 patients

FUNDAMENTO: É conhecido o envolvimento cardíaco em pacientes com distrofia muscular de Duchenne (DMD). O eletrocardiograma (ECG) apresenta algumas alterações típicas na DMD, fato que o torna um exame útil no diagnóstico da lesão cardíaca nessa patologia. OBJETIVO: Avaliar as alterações eletrocardiográficas em pacientes portadores de DMD, correlacionando-as com a idade da população estudada. MÉTODOS: Foram analisados os ECG de 131 pacientes com diagnóstico de DMD. Avaliaram-se diversas variáveis eletrocardiográficas, sendo os pacientes separados em dois grupos: aqueles com e sem alterações, por variável estudada. Fez-se a correlação desses dois grupos com a idade dos pacientes. Foram utilizados os critérios de Garson para estabelecer os parâmetros eletrocardiográficos de normalidade. RESULTADOS: O ECG estava anormal em 78,6 por cento dos pacientes. Todos apresentavam ritmo sinusal. Foram os seguintes os percentuais encontrados para as principais variáveis estudadas: PR curto = 18,3 por cento, ondas R anormais em V1 = 29,7 por cento, ondas Q anormais em V6 = 21,3 por cento, alterações da repolarização ventricular = 54,9 por cento, ondas QS anormais em paredes inferior e/ou lateral alta = 37,4 por cento, distúrbios de condução pelo ramo direito = 55,7 por cento, intervalo QT C prolongado = 35,8 por cento e alargamento do QRS = 23,6 por cento. O teste t não pareado foi utilizado para se estabelecer a correlação da idade com as variáveis eletrocardiográficas estudadas nos dois grupos e, apenas a variável alteração da repolarização mostrou diferença estatisticamente significante. CONCLUSÃO: As alterações eletrocardiográficas na DMD são frequentes, revelando comprometimento cardíaco precoce. Apenas a variável alteração da repolarização ventricular foi mais frequente, porém em faixa etária menor (p < 0,05).

BACKGROUND: Cardiac involvement is known to occur in patients with Duchenne muscular dystrophy (DMD). The electrocardiogram (ECG) shows some typical changes in DMD, which makes it a useful test for the diagnosis of cardiac lesion in this disease. OBJECTIVE: To evaluate the electrocardiographic changes in patients with DMD and to correlate these changes with the age of the population studied. METHODS: ECG of 131 patients diagnosed with DMD were examined. Several electrocardiographic variables were analyzed, and the patients were divided into two groups - one with and one without changes, for each variable studied. The correlation between the two groups and the age of the patients was analyzed. Garson's criteria were used to establish the electrocardiographic parameters of normality. RESULTS: ECG was abnormal in 78.6 percent of the patients. All showed normal sinus rhythm. The following percentages were found for the main variables studied: short PR interval = 18.3 percent; abnormal R waves in V1 = 29.7 percent; abnormal Q waves in V6 = 21.3 percent; abnormal ventricular repolarization = 54.9 percent; abnormal QS waves in inferior and/or upper lateral wall = 37.4 percent; conduction disturbances in right bundle branch = 55.7 percent; prolonged QT C interval = 35.8 percent, and wide QRS = 23.6 percent. Unpaired t test was used to establish the correlation between age and the electrocardiographic variables studied in the two groups. Statistically significant differences were found only for the abnormal repolarization variable. CONCLUSION: Electrocardiographic abnormalities are common in DMD, revealing early cardiac involvement. Only the abnormal ventricular repolarization variable was more frequent, however at a lower age range (p < 0.05).

[Duchenne muscular dystrophy: electrocardiographic analysis of 131 patients]. / Distrofia muscular de Duchenne: análise eletrocardiográfica de 131 pacientes.

BACKGROUND: Cardiac involvement is known to occur in patients with Duchenne muscular dystrophy (DMD). The electrocardiogram (ECG) shows some typical changes in DMD, which makes it a useful test for the diagnosis of cardiac lesion in this disease. OBJECTIVE: To evaluate the electrocardiographic changes in patients with DMD and to correlate these changes with the age of the population studied. METHODS: ECG of 131 patients diagnosed with DMD were examined. Several electrocardiographic variables were analyzed, and the patients were divided into two groups - one with and one without changes, for each variable studied. The correlation between the two groups and the age of the patients was analyzed. Garson's criteria were used to establish the electrocardiographic parameters of normality. RESULTS: ECG was abnormal in 78.6% of the patients. All showed normal sinus rhythm. The following percentages were found for the main variables studied: short PR interval = 18.3%; abnormal R waves in V1 = 29.7%; abnormal Q waves in V6 = 21.3%; abnormal ventricular repolarization = 54.9%; abnormal QS waves in inferior and/or upper lateral wall = 37.4%; conduction disturbances in right bundle branch = 55.7%; prolonged QT C interval = 35.8%, and wide QRS = 23.6%. Unpaired t test was used to establish the correlation between age and the electrocardiographic variables studied in the two groups. Statistically significant differences were found only for the abnormal repolarization variable. CONCLUSION: Electrocardiographic abnormalities are common in DMD, revealing early cardiac involvement. Only the abnormal ventricular repolarization variable was more frequent, however at a lower age range (p < 0.05).

Influência do processamento por via úmida e tipos de secagem sobre a composição, físico química e química do café (Coffea arabica L) / Influence of the wet processing and drying types on chemical and physicochemical composition of coffee (Coffea arabica L. )

O café (Coffea arabica L.) é um importante produto de exportação brasileira, por fazer parte do hábito alimentar da população de diversos países. Sua produção vem passando por transformações tecnológicas que têm como objetivo agregar valores qualitativos ao produto destinado tanto para mercado interno como externo. A exportação do café e de produtos alimentícios deve se adequar aos programas de qualidade estabelecidos por acordos políticos internacionais. Assim sendo, objetivou-se, nesse estudo, verificar a influência do método de preparo via úmida com tipos distintos de secagens, na obtenção do café cereja descascado, sobre a composição, físico-química e química do café. Houve influência da forma, preparo e tipo de secagem sobre as principais características estudadas. O café cereja descascado apresentou diferenças nos principais indicadores químicos físico-químicos e com uma superioridade para esse método de preparo com secagem exclusiva no terreiro, em diversos aspectos. Houve redução na condutividade elétrica, lixiviação de potássio e aumento da atividade da polifenoloxidase.

Coffee (Coffea arabica L.) is an important Brazilian export product, being part of the eating habit in several countries. Its production has experienced technological transformations, with the aim at adding quality values to the product destined to internal as well as to external market. The export of coffee and food products must adjust to the quality programs established by international political agreements. In this context, this work was carried out to verify the influence of the wet processing using different drying types on the obtentainment of the husked coffee cherry on the chemical and physicochemical composition of the coffee. There was influence of the preparation and the drying type methods on the main studied characteristics. The peeled red cherry coffee presented differences in the main chemical and physicochemical indicators, with a superiority in the preparation method with exclusive drying on the patio, in several aspects. Reduction in the electric conductivity and potassium leaching was observed as well as increase in the polyphenoloxidase activity.

Structural basis of GC-1 selectivity for thyroid hormone receptor isoforms.

BACKGROUND: Thyroid receptors, TRalpha and TRbeta, are involved in important physiological functions such as metabolism, cholesterol level and heart activities. Whereas metabolism increase and cholesterol level lowering could be achieved by TRbeta isoform activation, TRalpha activation affects heart rates. Therefore, beta-selective thyromimetics have been developed as promising drug-candidates for treatment of obesity and elevated cholesterol level. GC-1 [3,5-dimethyl-4-(4'-hydroxy-3'-isopropylbenzyl)-phenoxy acetic acid] has ability to lower LDL cholesterol with 600- to 1400-fold more potency and approximately two- to threefold more efficacy than atorvastatin (Lipitor(c)) in studies in rats, mice and monkeys. RESULTS: To investigate GC-1 specificity, we solved crystal structures and performed molecular dynamics simulations of both isoforms complexed with GC-1. Crystal structures reveal that, in TRalpha Arg228 is observed in multiple conformations, an effect triggered by the differences in the interactions between GC-1 and Ser277 or the corresponding asparagine (Asn331) of TRbeta. The corresponding Arg282 of TRbeta is observed in only one single stable conformation, interacting effectively with the ligand. Molecular dynamics support this model: our simulations show that the multiple conformations can be observed for the Arg228 in TRalpha, in which the ligand interacts either strongly with the ligand or with the Ser277 residue. In contrast, a single stable Arg282 conformation is observed for TRbeta, in which it strongly interacts with both GC-1 and the Asn331. CONCLUSION: Our analysis suggests that the key factors for GC-1 selectivity are the presence of an oxyacetic acid ester oxygen and the absence of the amino group relative to T3. These results shed light into the beta-selectivity of GC-1 and may assist the development of new compounds with potential as drug candidates to the treatment of hypercholesterolemia and obesity.

Condições de vida e saúde da população idosa do município de Guaramiranga-CE / Living conditions and health of the elderly population of the municipality of Guaramiranga, CE

desenvolvimento, entre eles o Brasil, nas últimas décadas. Estudos de basepopulacional têm sido realizados e podem ser utilizados como ferramenta para o planejamento das políticas públicas direcionadas aos idosos. O objetivo deste estudo foi conhecer as condições de vidas e saúde da população idosa do município de Guaramiranga, Ceará, em 2007. Tratou-se de um estudo transversal de basepopulacional, em que foi aplicado um questionário adaptado do Projeto SABE, em 438 idosos residentes no município. A análise descritiva das variáveis do estudo foi efetuada através da determinação de medidas de tendência central e de dispersão para as variáveis contínuas e de distribuições de freqüência para as variáveiscategóricas. O teste estatístico do qui-quadrado foi empregado na análise dapresença de associações entre as variáveis do estudo. A análise dos dados foi efetuada com o pacote estatístico SPSS 12.0. Quanto ao perfil sócio-demográfico, 60,3 por cento (n=264) da população idosa pertence ao sexo feminino e 39,7 por cento (n=174) aosexo masculino, sendo que a faixa etária predominante corresponde aos 60-69 anos de idade. Os idosos apresentam baixa escolaridade, com 42,7 por cento de analfabetos e o percentual de aposentados é de 87,42 por cento (n=383). Com relação à saúde autoreferida, 208 (47,5 por cento) idosos referiram saúde entre excelente e boa. Entre os idosos de 60-69 anos, mais de 50 por cento considerou sua saúde como excelente ou boa,enquanto, na faixa etária de 70-79 anos, esse valor correspondeu a 45 por cento e, entre aqueles de 80 anos ou mais, foi de cerca de 31 por cento. Com relação à auto-referência a doenças crônicas, 240 idosos (55,0 por cento) se declararam hipertensos, 69 (16,0 por cento) informaram ser diabéticos e 35 (8,1 por cento) referiram doenças crônicas do pulmão.

Crystal structures of Leptospira interrogans FAD-containing ferredoxin-NADP+ reductase and its complex with NADP+.

BACKGROUND: Ferredoxin-NADP(H) reductases (FNRs) are flavoenzymes that catalyze the electron transfer between NADP(H) and the proteins ferredoxin or flavodoxin. A number of structural features distinguish plant and bacterial FNRs, one of which is the mode of the cofactor FAD binding. Leptospira interrogans is a spirochaete parasitic bacterium capable of infecting humans and mammals in general. Leptospira interrogans FNR (LepFNR) displays low sequence identity with plant (34% with Zea mays) and bacterial (31% with Escherichia coli) FNRs. However, LepFNR contains all consensus sequences that define the plastidic class FNRs. RESULTS: The crystal structures of the FAD-containing LepFNR and the complex of the enzyme with NADP+, were solved and compared to known FNRs. The comparison reveals significant structural similarities of the enzyme with the plastidic type FNRs and differences with the bacterial enzymes. Our small angle X-ray scattering experiments show that LepFNR is a monomeric enzyme. Moreover, our biochemical data demonstrate that the LepFNR has an enzymatic activity similar to those reported for the plastidic enzymes and that is significantly different from bacterial flavoenzymes, which display lower turnover rates. CONCLUSION: LepFNR is the first plastidic type FNR found in bacteria and, despite of its low sequence similarity with plastidic FNRs still displays high catalytic turnover rates. The typical structural and biochemical characteristics of plant FNRs unveiled for LepFNR support a notion of a putative lateral gene transfer which presumably offers Leptospira interrogans evolutionary advantages. The wealth of structural information about LepFNR provides a molecular basis for advanced drugs developments against leptospirosis.

O cuidado à equipe multidisciplinar / The care for the multidisciplinary team

Dentro da conceituação sobre o que constitui um trabalho suficientemente bom, que satisfaça as necessidades clínicas que emanam do paciente com transtorno alimentar (TA), uma reflexão nascente se impãe como parte dessas exigências: o cuidado à equipe multidisciplinar, não tendo este, caráter dispensável, mas absolutamente indispensável como instrumental que visa alicerçar melhor, os profissionais envolvidos nesta tarefa. A autora, psicanalista, sonda o relacionamento medico - paciente atual, inserido na cultura do vazio, onde ambos correm risco de se encontrarem num lugar esvaziado de ôsignificadosõ, envolvidos na árida função de contar calorias e da mensuração corporal. Tomando como exemplo um caso de obesidade mórbida a analista reflete as tensães vividas pelo médico no contato com os pacientes, e o risco de ôburn-outõ, um tipo de sofrimento mental grave que pode acometer o profissional nestas situaçães. Propãe algumas soluçães para este problema, que visam a ampliação do espaço mental do médico, necessário ao abrigo do paciente que lhe pede socorro.

Within the conceptual approach to what represents a sufficiently good intervention that will satisfy the clinical needs of patients with eating disorders (ED), an incipient reflection becomes part of these requirements: the care for the multidisciplinary team. This is not of a dispensable nature, but is absolutely indispensable as an instrument aiming at a better foundation for the professionals involved in this task. The author, a psychoanalyst, examines the current doctor-patient relationship, which is inserted in the culture of vacuum, where both are at risk to be in a place emptied of “meanings” and to be involved in the arid function of counting calories and performing body measurements. Taking as an example a case of morbid obesity, the analyst reflects on the tensions experienced by the doctor in his contact with the patients and on the riskof burn-out, a type of severe mental suffering that may affect the professional in these situations.The author proposes some solutions for this problem aiming at the expansion of the mental space of the doctor, which is necessary to shelter the patient who asks for help

Structural rearrangements in the thyroid hormone receptor hinge domain and their putative role in the receptor function.

The thyroid hormone receptor (TR) D-domain links the ligand-binding domain (LBD, EF-domain) to the DNA-binding domain (DBD, C-domain), but its structure, and even its existence as a functional unit, are controversial. The D domain is poorly conserved throughout the nuclear receptor family and was originally proposed to comprise an unfolded hinge that facilitates rotation between the LBD and the DBD. Previous TR LBD structures, however, have indicated that the true unstructured region is three to six amino acid residues long and that the D-domain N terminus folds into a short amphipathic alpha-helix (H0) contiguous with the DBD and that the C terminus of the D-domain comprises H1 and H2 of the LBD. Here, we solve structures of TR-LBDs in different crystal forms and show that the N terminus of the TRalpha D-domain can adopt two structures; it can either fold into an amphipathic helix that resembles TRbeta H0 or form an unstructured loop. H0 formation requires contacts with the AF-2 coactivator-binding groove of the neighboring TR LBD, which binds H0 sequences that resemble coactivator LXXLL motifs. Structural analysis of a liganded TR LBD with small angle X-ray scattering (SAXS) suggests that AF-2/H0 interactions mediate dimerization of this protein in solution. We propose that the TR D-domain has the potential to form functionally important extensions of the DBD and LBD or unfold to permit TRs to adapt to different DNA response elements. We also show that mutations of the D domain LXXLL-like motif indeed selectively inhibit TR interactions with an inverted palindromic response element (F2) in vitro and TR activity at this response element in cell-based transfection experiments.