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41.
Vega-López A Ortiz-Ordóñez E Uría-Galicia E Mendoza-Santana EL Hernández-Cornejo R Atondo-Mexia R García-Gasca A García-Latorre E Domínguez-López ML 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,147(3):731-742
Goodeid fish have matrotrophic viviparity, and unlike lecitotrophic fish, yolk loss forces the female to provide the nutritional requirements for embryonic development. Vitellogenin (VTG) is the yolk precursor protein synthesized in the maternal liver, but there is only circumstantial evidence regarding VTG supply during the ontogenesis of bony fish with matrotrophic viviparity. Therefore, the goal of the present study was to identify and quantify VTG during gestation of the black fin goodeid Girardinichthys viviparus and the butterfly split-fin goodeid Ameca splendens. Females at different gonadic developmental stages were selected in order to evaluate VTG mRNA expression in the maternal liver using RT-PCR; VTG quantification in maternal muscle and liver, as well as in the embryos, was done using ELISA, and immunohistochemical detection of VTG was done in the black fin goodeid. The results suggest that VTG supplies nutrients during embryonic development of both species, which have different life histories. It is possible that the transition from lecitotrophy to matrotrophic viviparity in bony fish with intraluminal gestation involved adaptive transition strategies that included changes in the relationship between oocytes and follicular cells, as well as a gradual loss of VTG synthesis during embryonic development. 相似文献
42.
Armando Vega-Lpez Marcela Galar-Martínez Fausto Alejandro Jimnez-Orozco Ethel García-Latorre Maria Lilia Domínguez-Lpez 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2007,146(4):672
Polychlorinated biphenyls (PCBs) are persistent xenobiotics within aquatic environments, which elicit diverse toxic effects such as induction of oxidative stress. Despite numerous earlier studies, no detailed information exists on the toxic response by different sexes in fish. The aim of this study was to determine sex-linked differences in oxidative stress response and antioxidant defenses in Girardinichthys viviparus, an endangered fish endemic to Mexico, when exposed to sub-lethal concentrations of waterborne PCBs. The biological markers evaluated were lipid peroxidation (LPOX), superoxide dismutase (SOD) and catalase (CAT) activity. Adult eight-month-old specimens born in the laboratory were exposed to ½ of the LC0 (0.92 mg PCBs/L) in semi-hard synthetic water and sacrificed on days 1, 2, 4, 8 and 16 for biomarker assays. Sex-linked differences were observed in the control fish with respect to all three factors assayed. PCBs elicited significant (p < 0.01) time- and sex-dependent LPOX levels which were higher in the case of males. In PCB-treated G. viviparus, SOD activity was depressed in both sexes and appears to return to pre-exposure levels after 16 days in males only. In contrast, CAT was significantly induced (p < 0.01) in both sexes. This enzyme may be responsible for balancing oxidative stress and antioxidant defenses under experimental conditions. PCBs at sub-lethal concentrations are hazardous to both sexes of G. viviparus since these compounds are able to induce liver LPOX and changes in the antioxidant defense activities. The relationship between these biomarkers and cytochrome P450 and CYP1A induction is also discussed. 相似文献
43.
Neurotrophins are structurally related proteins regulating brain development and function. Molecular evolution studies of neurotrophins and their receptors are essential for understanding the mechanisms underlying the coevolution processes of these gene families and how they correlate with the increased complexity of the vertebrate nervous system. In order to improve our current knowledge of the molecular evolution of neurotrophins and receptors, we have collected all information available in the literature and analyzed the genome database for each of them. Statistical analysis of aminoacid and nucleotide sequences of the neurotrophin and Trk family genes was applied to both complete genes and mature sequences, and different phylogenetic methods were used to compare aminoacid and nucleotide sequences variability among the different species. All collected data favor a model in which several rounds of genome duplications might have facilitated the generation of the many different neurotrophins and the acquisition of specific different functions correlated with the increased complexity of the vertebrate nervous system during evolution. We report findings that refine the structure of the evolutionary trees for neurotrophins and Trk receptors families, indicate different rates of evolution for each member of the two families, and newly demonstrate that the NGF-like genes found in Fowlpox and Canarypox viruses are closely related to reptile NGF. 相似文献
44.
Xie H Vucetic S Iakoucheva LM Oldfield CJ Dunker AK Obradovic Z Uversky VN 《Journal of proteome research》2007,6(5):1917-1932
Currently, the understanding of the relationships between function, amino acid sequence, and protein structure continues to represent one of the major challenges of the modern protein science. As many as 50% of eukaryotic proteins are likely to contain functionally important long disordered regions. Many proteins are wholly disordered but still possess numerous biologically important functions. However, the number of experimentally confirmed disordered proteins with known biological functions is substantially smaller than their actual number in nature. Therefore, there is a crucial need for novel bionformatics approaches that allow projection of the current knowledge from a few experimentally verified examples to much larger groups of known and potential proteins. The elaboration of a bioinformatics tool for the analysis of functional diversity of intrinsically disordered proteins and application of this data mining tool to >200 000 proteins from the Swiss-Prot database, each annotated with at least one of the 875 functional keywords, was described in the first paper of this series (Xie, H.; Vucetic, S.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V.N. Functional anthology of intrinsic disorder. 1. Biological processes and functions of proteins with long disordered regions. J. Proteome Res. 2007, 5, 1882-1898). Using this tool, we have found that out of the 710 Swiss-Prot functional keywords associated with at least 20 proteins, 262 were strongly positively correlated with long intrinsically disordered regions, and 302 were strongly negatively correlated. Illustrative examples of functional disorder or order were found for the vast majority of keywords showing strongest positive or negative correlation with intrinsic disorder, respectively. Some 80 Swiss-Prot keywords associated with disorder- and order-driven biological processes and protein functions were described in the first paper (see above). The second paper of the series was devoted to the presentation of 87 Swiss-Prot keywords attributed to the cellular components, domains, technical terms, developmental processes, and coding sequence diversities possessing strong positive and negative correlation with long disordered regions (Vucetic, S.; Xie, H.; Iakoucheva, L. M.; Oldfield, C. J.; Dunker, A. K.; Obradovic, Z.; Uversky, V. N. Functional anthology of intrinsic disorder. 2. Cellular components, domains, technical terms, developmental processes, and coding sequence diversities correlated with long disordered regions. J. Proteome Res. 2007, 5, 1899-1916). Protein structure and functionality can be modulated by various post-translational modifications or/and as a result of binding of specific ligands. Numerous human diseases are associated with protein misfolding/misassembly/misfunctioning. This work concludes the series of papers dedicated to the functional anthology of intrinsic disorder and describes approximately 80 Swiss-Prot functional keywords that are related to ligands, post-translational modifications, and diseases possessing strong positive or negative correlation with the predicted long disordered regions in proteins. 相似文献
45.
Lilia Neri Paola Pittia Gianni Bertolo Danila Torreggiani Giampiero Sacchetti 《Food biophysics》2011,6(2):281-287
Maltodextrins influenced the enzymatic activity in aqueous solutions by affecting the water activity (aw) and mobility as described by viscosity and T’g. In diluted solutions, viscosity being equal, (1) maltodextrin with dextrose
equivalents (DE) of 33 was more effective than glucose in limiting horseradish peroxidase (HRP) activity; (2) an increase
in the maltodextrin chain length from DE 33 to DE 8.7 did not further limited enzymatic activity; (3) the maltodextrin with
the highest chain length (DE 2.5) determined the highest enzyme inhibition. In general, the increase of molecular weight negatively
affected the HRP activity by increasing the viscosity and T’g (decreasing molecular mobility) but it positively affected the
aw and, in some cases, this compensated the HRP activity inhibition. In concentrated solutions (apparent viscosity ≈ 40 mPa s)
the HRP activity decreased with the increase of the maltodextrin molecular weight, and it showed a dependence on T’g which
could be described by a William, Landel and Ferry (WLF)-type equation. On the contrary, in the solution added with the maltodextrin
with the highest chain length (DE 2.5) the HRP activity was much higher than that predicted by the WLF-type equation. The
maltodextrin with DE 2.5 contains intact starch fragments and in water forms a suspension. In such a discontinuous system,
the viscosity in the vicinity of the protein is lower than the bulk viscosity, and thus, the enzyme activity is higher than
expected. Moreover, since T’g is a property of the soluble phase, it does not explain the mobility in discontinuous systems. 相似文献
46.
Jacobsson JA Almén MS Benedict C Hedberg LA Michaëlsson K Brooks S Kullberg J Axelsson T Johansson L Ahlström H Fredriksson R Lind L Schiöth HB 《PloS one》2011,6(5):e20158
Background
The rs9939609 single-nucleotide polymorphism (SNP) in the fat mass and obesity (FTO) gene has previously been associated with higher BMI levels in children and young adults. In contrast, this association was not found in elderly men. BMI is a measure of overweight in relation to the individuals'' height, but offers no insight into the regional body fat composition or distribution.Objective
To examine whether the FTO gene is associated with overweight and body composition-related phenotypes rather than BMI, we measured waist circumference, total fat mass, trunk fat mass, leg fat mass, visceral and subcutaneous adipose tissue, and daily energy intake in 985 humans (493 women) at the age of 70 years. In total, 733 SNPs located in the FTO gene were genotyped in order to examine whether rs9939609 alone or the other SNPs, or their combinations, are linked to obesity-related measures in elderly humans.Design
Cross-sectional analysis of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS) cohort.Results
Neither a single SNP, such as rs9939609, nor a SNP combination was significantly linked to overweight, body composition-related measures, or daily energy intake in elderly humans. Of note, these observations hold both among men and women.Conclusions
Due to the diversity of measurements included in the study, our findings strengthen the view that the effect of FTO on body composition appears to be less profound in later life compared to younger ages and that this is seemingly independent of gender. 相似文献47.
Valverde-Islas LE Arrangoiz E Vega E Robert L Villanueva R Reynoso-Ducoing O Willms K Zepeda-Rodríguez A Fortoul TI Ambrosio JR 《PloS one》2011,6(3):e14754
Background
Flame cells are the terminal cells of protonephridial systems, which are part of the excretory systems of invertebrates. Although the knowledge of their biological role is incomplete, there is a consensus that these cells perform excretion/secretion activities. It has been suggested that the flame cells participate in the maintenance of the osmotic environment that the cestodes require to live inside their hosts. In live Platyhelminthes, by light microscopy, the cells appear beating their flames rapidly and, at the ultrastructural, the cells have a large body enclosing a tuft of cilia. Few studies have been performed to define the localization of the cytoskeletal proteins of these cells, and it is unclear how these proteins are involved in cell function.Methodology/Principal Findings
Parasites of two different developmental stages of T. solium were used: cysticerci recovered from naturally infected pigs and intestinal adults obtained from immunosuppressed and experimentally infected golden hamsters. Hamsters were fed viable cysticerci to recover adult parasites after one month of infection. In the present studies focusing on flame cells of cysticerci tissues was performed. Using several methods such as video, confocal and electron microscopy, in addition to computational analysis for reconstruction and modeling, we have provided a 3D visual rendition of the cytoskeletal architecture of Taenia solium flame cells.Conclusions/Significance
We consider that visual representations of cells open a new way for understanding the role of these cells in the excretory systems of Platyhelminths. After reconstruction, the observation of high resolution 3D images allowed for virtual observation of the interior composition of cells. A combination of microscopic images, computational reconstructions and 3D modeling of cells appears to be useful for inferring the cellular dynamics of the flame cell cytoskeleton. 相似文献48.
49.
In this study, the production of recombinant Hepatitis C virus (HCV) derived proteins from transformed Saccharomyces cerevisiae yeast cells is reported. Three different yeast strains (GRF18U, BY4743-4A and CENPK 113-5D) have been transformed for the intracellular expression of five antigens of different dimensions (from 32.8 to 85.2 kDa), all derived from the non-structural (NS) region of different HCV viruses' genotypes and posed under the control of a glycolytic promoter. The putative trans-membrane domains contained in four antigens seem responsible of their accumulation as protein aggregates. Good productions of the smaller and of the bigger antigens (50 and 30 mgl(-1), respectively) have been observed in simple flask batch cultures. Productions are strongly dependent from the genetic background of the yeast host and from the cellular localization of the antigen, while they appear independent from the growth rate of the transformed hosts. For every recombinant antigen tested, the highest production levels were achieved with the CENPK 113-5D-host strain, while the GRF18U strain shows symptoms of a heavily stressed phenotype. 相似文献
50.
In spite of its widespread use, benznidazole's (BNZ) toxicity and low efficacy remains as major drawbacks that impair successful treatments against Chagas disease. Previously, attempting to increase the selectivity and reduce its toxicity on infected tissues, multilamellar liposomes (MLV) composed of hydrogenated soybean phosphatidylcholine (HSPC): distearoyl-phosphatidylglycerol (DSPG): cholesterol (CHOL) 2:1:2 mol:mol loaded with BNZ (MLV-BNZ) were designed. In this work we compared different properties of MLV-BNZ with those of BNZ. Opposite to other hydrophobic drugs, the results indicated that slight changes of BNZ's association degree to proteins and lipoproteins should not modify the percentage of unbound drug available to exert pharmacological action. On the other hand, when loaded in MLV, BNZ reduced its association to plasma proteins in 45% and became refractory to the sinking effect of blood, dropping 4.5 folds. Additionally, when loaded in MLV, BNZ had higher volume distribution (160 +/- 20 vs 102 +/- 15 ml/kg) and total clearance (35.23 +/- 2.3 vs 21.9 +/- 1.4 ml/h.kg), and lower concentration-time curve (7.23 +/- 0.2 vs 9.16 +/- 0.5 microg.h/ml) than BNZ. Hence, these studies showed that for MLV-BNZ, the amount of BNZ can be substantially increased, from 25 to 70%, being this formulation more rapidly cleared from circulation than free drug; also due to the lower interaction with blood components, lower side effects can be expected. 相似文献