121 research outputs found

    Central domain deletions affect the SAXS solution structure and function of Yeast Hsp40 proteins Sis1 and Ydj1

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    Background: Ydj1 and Sis1 are structurally and functionally distinct Hsp40 proteins of the yeast cytosol. Sis1 is an essential gene whereas the ydj1 gene is essential for growth at elevated temperatures and cannot complement sis1 gene deletion. Truncated polypeptides capable of complementing the sis1 gene deletion comprise the J-domain of either Sis1 or Ydj1 connected to the G/F region of Sis1 (but not Ydj1). Sis1 mutants in which the G/F was deleted but G/M maintained were capable of complementing the sis1 gene deletion. Results: To investigate the relevance of central domains on the structure and function of Ydj1 and Sis1 we prepared Sis1 constructs deleting specific domains. The mutants had decreased affinity for heated luciferase but were equally capable of stimulating ATPase activity of Hsp70. Detailed low resolution structures were obtained and the overall flexibility of Hsp40 and its mutants were assessed using SAXS methods. Deletion of either the G/M or the G/M plus CTDI domains had little impact on the quaternary structure of Sis1 analyzed by the SAXS technique. However, deletion of the ZFLR-CTDI changed the relative position of the J-domains in Ydj1 in such a way that they ended up resembling that of Sis1. The results revealed that the G/F and G/M regions are not the only flexible domains. All model structures exhibit a common clamp-like conformation. Conclusions: Our results suggest that the central domains, previously appointed as important features for substrate binding, are also relevant keeping the J-domains in their specific relative positions. The clamp-like architecture observed seems also to be favorable to the interactions of Hsp40 with Hsp70

    Environmental Law and Policy to Control Marine Invasive Species: The Potential Role of Environmental Impact Assessment for Enforcing the Law of the Sea in Brazil

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    42 pagesAs transportation of cargo by ships constitutes ninety-five percent of all international trade, several negative externalities on marine pollution from those activities remain only poorly addressed. One of the most critical challenges of marine pollution has been the problem posed by marine invasive species transported by ships’ ballast water. To tackle this issue, the International Maritime Organization approved an international convention called the International Convention for the Control and Management of Ships’ Ballast Water and Sediments, which entered into force globally on September 9, 2017, and offers technical guidance to vessels on exchanges or performance standards for ballast water treatment. Besides scientific debates on the technical justifications for those solutions, a major difficulty is the actual enforcement of the IMO Convention rules, mostly based on formal checks on paper registries by coastal authorities, keeping the issue of ballast water management largely unsolved

    From Conformation to interaction: techniques to explore the Hsp70/hsp90 network

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    Proteins participate in almost every cell physiological function, and to do so, they need to reach a state that allows its function by folding and/or exposing surfaces of interactions. Spontaneous folding in the cell is in general hindered by its crowded and viscous environment, which favors misfolding and nonspecific and deleterious self-interactions. To overcome this, cells have a system, in which Hsp70 and Hsp90 play a central role to aid protein folding and avoid misfolding. The topics of this review include the biophysical tools used for monitoring protein-ligand and protein-protein interactions and also some important results related to the study of molecular chaperones and heat shock proteins (Hsp), with a focus on the Hsp70/Hsp90 network. The biophysical tools and their use to probe the conformation and interaction of Hsp70 and Hsp90 are briefly reviewed168735753CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPES

    Characterization of Acrocarpus fraxinifolius wood submitted to heat treatment

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    Aiming to provide greater visibility for the wood species Acrocarpus fraxinifolius, the present study sought to analyze the influence of heat treatment on an industrial scale applied to wood species, also popularly known as Indian cedar. The heat treatment was carried out in an autoclave, with temperature and pressure control, and with saturated steam injection, for temperatures 155 ÂșC, 165 ÂșC, 175 ÂșC, and 185 ÂșC. Physical, chemical, and mechanical tests were carried out for the analyzed wood. The content of holocellulose and total lignin decreased, while the content of extractives showed a substantial increase. The density increased after the heat treatment, however the treated wood showed cracks, and these cracks influenced the significant loss of the values of the mechanical properties of compression, tension, and flexion. The shear showed strength gain for the temperature of 155 ÂșC, and the wood treated at 165 ÂșC was equivalent to untreated wood. The woods submitted to temperatures of 175 ÂșC and 185 ÂșC presented strength losses. The heat treatment in question contributes to increase the visibility, use and market value of wood

    A mild and efficient method for the preparation of 3-(2'-Aminoaryl)pyrazoles from 4-chloroquinolines

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    We describe a mild and efficient method for the formation of 3-(2'-aminoaryl)pyrazoles in excellent yields from reactions of 4-chloroquinolines with hydrazine. These heterocyclic ring opening reactions occur under much milder conditions then previously described

    DXA, bioelectrical impedance, ultrasonography and biometry for the estimation of fat and lean mass in cats during weight loss

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    Background: Few equations have been developed in veterinary medicine compared to human medicine to predict body composition. The present study was done to evaluate the influence of weight loss on biometry (BIO), bioimpedance analysis (BIA) and ultrasonography (US) in cats, proposing equations to estimate fat (FM) and lean (LM) body mass, as compared to dual energy x-ray absorptiometry (DXA) as the referenced method. For this were used 16 gonadectomized obese cats (8 males and 8 females) in a weight loss program. DXA, BIO, BIA and US were performed in the obese state (T0; obese animals), after 10% of weight loss (T1) and after 20% of weight loss (T2). Stepwise regression was used to analyze the relationship between the dependent variables (FM, LM) determined by DXA and the independent variables obtained by BIO, BIA and US. The better models chosen were evaluated by a simple regression analysis and means predicted vs. determined by DXA were compared to verify the accuracy of the equations. Results: The independent variables determined by BIO, BIA and US that best correlated (p < 0.005) with the dependent variables (FM and LM) were BW (body weight), TC (thoracic circumference), PC (pelvic circumference), R (resistance) and SFLT (subcutaneous fat layer thickness). Using Mallows'Cp statistics, p value and r(2), 19 equations were selected (12 for FM, 7 for LM); however, only 7 equations accurately predicted FM and one LM of cats. Conclusions: The equations with two variables are better to use because they are effective and will be an alternative method to estimate body composition in the clinical routine. For estimated lean mass the equations using body weight associated with biometrics measures can be proposed. For estimated fat mass the equations using body weight associated with bioimpedance analysis can be proposed.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao PauloBrazilFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo-Brazil [04/15416-9]Mogiana Alimentos S.A. (Guabi), Campinas, BrazilMogiana Alimentos S.A. (Guabi), Campinas, Brazi

    Ultrasonography of the distal limbs in Nellore and Girolando calves 8 to 12 months of age

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    Submitted by Franciele Moreira ([email protected]) on 2018-01-08T13:43:58Z No. of bitstreams: 2 Artigo - Pryscilla Vanessa Rodrigues Gonçalves - 2014.pdf: 738775 bytes, checksum: 17c42f29f233f408ef568a5c45b1b787 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Approved for entry into archive by Luciana Ferreira ([email protected]) on 2018-01-08T14:49:52Z (GMT) No. of bitstreams: 2 Artigo - Pryscilla Vanessa Rodrigues Gonçalves - 2014.pdf: 738775 bytes, checksum: 17c42f29f233f408ef568a5c45b1b787 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)Made available in DSpace on 2018-01-08T14:49:52Z (GMT). No. of bitstreams: 2 Artigo - Pryscilla Vanessa Rodrigues Gonçalves - 2014.pdf: 738775 bytes, checksum: 17c42f29f233f408ef568a5c45b1b787 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2014Background: Ultrasonography can be used anywhere and allows rapid, noninvasive differentiation of soft tissue structures of the musculoskeletal system. The objectives of this study were to describe the ultrasonographic appearance of the structures of the metacarpo-/metatarsophalangeal and the interphalangeal joints, the appearance of the growth plates of the distal metacarpus/metatarsus and of the proximal phalanx and to measure the cross-sectional dimensions of the DDFT and SDFT in Nellore and Girolando calves eight to 12 months of age. Results: In the longitudinal dorsal view the common digital extensor tendon and the digital extensor tendon were depicted as echogenic parallel fiber bundles located directly under the skin. The joint spaces appeared as anechoic interruptions of the hyperechogenic bone surfaces. The normal amount of synovial fluid could not be depicted. The growth plates were seen as anechoic interruptions of the bone surface proximal and distal to the fetlock joint space. In transverse sonograms of the distal palmar/plantar regions, the flexor tendons and branchs of the suspensory ligament were imaged as echogenic structures. The lumen of the digital flexor tendon sheath could not be imaged in these normal cattle. The thin digital distal annular ligament and the reversal of positions of the DDFT and SDFT could be appreciated. No significant differences were found between the cross-sectional measurements of the DDFT and the SDFT from Nellore and Girolando in any age, thoracic/pelvic limbs, right/left sides and lateral/medial digits. Conclusions: The results of this study establish important ultrasonographic reference data of the normal structures of the distal limbs and the normal dimensions of the flexor tendons in Nellore and Girolando calves for use in clinical practice

    A straightforward multiallelic significance test for the Hardy-Weinberg equilibrium law

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    Much forensic inference based upon DNA evidence is made assuming Hardy-Weinberg Equilibrium (HWE) for the genetic loci being used. Several statistical tests to detect and measure deviation from HWE have been devised, and their limitations become more obvious when testing for deviation within multiallelic DNA loci. The most popular methods-Chi-square and Likelihood-ratio tests-are based on asymptotic results and cannot guarantee a good performance in the presence of low frequency genotypes. Since the parameter space dimension increases at a quadratic rate on the number of alleles, some authors suggest applying sequential methods, where the multiallelic case is reformulated as a sequence of “biallelic” tests. However, in this approach it is not obvious how to assess the general evidence of the original hypothesis; nor is it clear how to establish the significance level for its acceptance/rejection. In this work, we introduce a straightforward method for the multiallelic HWE test, which overcomes the aforementioned issues of sequential methods. The core theory for the proposed method is given by the Full Bayesian Significance Test (FBST), an intuitive Bayesian approach which does not assign positive probabilities to zero measure sets when testing sharp hypotheses. We compare FBST performance to Chi-square, Likelihood-ratio and Markov chain tests, in three numerical experiments. The results suggest that FBST is a robust and high performance method for the HWE test, even in the presence of several alleles and small sample sizes

    Characterization of individuals at high risk of developing melanoma in Latin America: bases for genetic counseling in melanoma

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    PURPOSE: CDKN2A is the main high-risk melanoma-susceptibility gene, but it has been poorly assessed in Latin America. We sought to analyze CDKN2A and MC1R in patients from Latin America with familial and sporadic multiple primary melanoma (SMP) and compare the data with those for patients from Spain to establish bases for melanoma genetic counseling in Latin America. METHODS: CDKN2A and MC1R were sequenced in 186 Latin American patients from Argentina, Brazil, Chile, Mexico, and Uruguay, and in 904 Spanish patients. Clinical and phenotypic data were obtained. RESULTS: Overall, 24 and 14% of melanoma-prone families in Latin America and Spain, respectively, had mutations in CDKN2A. Latin American families had CDKN2A mutations more frequently (P = 0.014) than Spanish ones. Of patients with SMP, 10% of those from Latin America and 8.5% of those from Spain had mutations in CDKN2A (P = 0.623). The most recurrent CDKN2A mutations were c.-34G>T and p.G101W. Latin American patients had fairer hair (P = 0.016) and skin (P < 0.001) and a higher prevalence of MC1R variants (P = 0.003) compared with Spanish patients. CONCLUSION: The inclusion criteria for genetic counseling of melanoma in Latin America may be the same criteria used in Spain, as suggested in areas with low to medium incidence, SMP with at least two melanomas, or families with at least two cases among first- or second-degree relatives.Genet Med 18 7, 727-736
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