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Brand G.D.,Laboratorio Of Espectrometria Of Massa | Brand G.D.,University of Glasgow | Magalhaes M.T.Q.,Laboratorio Of Espectrometria Of Massa | Tinoco M.L.P.,Laboratorio Of Transferencia E Expressao Of Genes | And 5 more authors.
PLoS ONE | Year: 2012

Starting from the premise that a wealth of potentially biologically active peptides may lurk within proteins, we describe here a methodology to identify putative antimicrobial peptides encrypted in protein sequences. Candidate peptides were identified using a new screening procedure based on physicochemical criteria to reveal matching peptides within protein databases. Fifteen such peptides, along with a range of natural antimicrobial peptides, were examined using DSC and CD to characterize their interaction with phospholipid membranes. Principal component analysis of DSC data shows that the investigated peptides group according to their effects on the main phase transition of phospholipid vesicles, and that these effects correlate both to antimicrobial activity and to the changes in peptide secondary structure. Consequently, we have been able to identify novel antimicrobial peptides from larger proteins not hitherto associated with such activity, mimicking endogenous and/or exogenous microorganism enzymatic processing of parent proteins to smaller bioactive molecules. A biotechnological application for this methodology is explored. Soybean (Glycine max) plants, transformed to include a putative antimicrobial protein fragment encoded in its own genome were tested for tolerance against Phakopsora pachyrhizi, the causative agent of the Asian soybean rust. This procedure may represent an inventive alternative to the transgenic technology, since the genetic material to be used belongs to the host organism and not to exogenous sources. © 2012 Brand et al.


Barbosa E.F.,Laboratorio Of Espectrometria Of Massa | Barbosa E.F.,University of Brasilia | Silva L.P.,Laboratorio Of Espectrometria Of Massa | Silva L.P.,University of Brasilia
Journal of Membrane Science | Year: 2012

Synthetic polymeric porous membranes (PPMs) have been widely used in several areas. Here, PPMs were scrutinized in a systematic approach over their mechanostructural features, chemical composition and filtration efficiency. Four types of PPMs (nitrocellulose, nylon, PTFE, and PVDF) were analyzed by single point force spectroscopy (FS), atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and energy-dispersive X-ray spectroscopy (EDS). PTFE membrane showed discrepancy between top and bottom parts related to FS parameters. The most irregular topography assessed by AFM was presented by nylon membrane showing out values for roughness parameters (Ra, Rz, and Rp) higher that all other membranes. Determination of filtration efficiency by spectrophotometric measurements did not allow us to visualize tendencies for incrustation of compounds. Nevertheless, AFM and SEM images of PPMs before and after filtration tests showed significant topographical differences. FTIR and EDS analyses also evidenced PPMs chemical and elemental composition, respectively. The use of these approaches focusing on nanometric aspects of each membrane can reveal new possibilities concerning their characterization and applications. It arises as an alternative tool for quality control evaluation, or search for support for biomolecules immobilization. © 2012 Elsevier B.V.


de Magalhaes M.T.Q.,Laboratorio Of Espectrometria Of Massa | de Magalhaes M.T.Q.,University of Brasilia | de Magalhaes M.T.Q.,The John B Pierce Laboratory | Barbosa E.A.,Laboratorio Of Espectrometria Of Massa | And 7 more authors.
PLoS ONE | Year: 2013

Skin secretion of Hypsiboas punctatus is the source of a complex mixture of bioactive compounds where peptides and small proteins prevail, similarly to many other amphibians. Among dozens of molecules isolated from H. punctatus in a proteomic based approach, we report here the structural and functional studies of a novel peptide named Phenylseptin (FFFDTLKNLAGKVIGALT-NH2) that was purified as two naturally occurring D- and L-Phes configurations. The amino acid epimerization and C-terminal amidation for both molecules were confirmed by a combination of techniques including reverse-phase UFLC, ion mobility mass spectrometry, high resolution MS/MS experiments, Edman degradation, cDNA sequencing and solid-phase peptide synthesis. RMSD analysis of the twenty lowest-energy 1H NMR structures of each peptide revealed a major 90° difference between the two backbones at the first four N-terminal residues and substantial orientation changes of their respective side chains. These structural divergences were considered to be the primary cause of the in vitro quantitative differences in antimicrobial activities between the two molecules. Finally, both molecules elicited equally aversive reactions in mice when delivered orally, an effect that depended entirely on peripheral gustatory pathways. © 2013 Magalhães et al.


Joanitti G.A.,Laboratorio Of Espectrometria Of Massa | Joanitti G.A.,University of Brasilia | Silva L.P.,Laboratorio Of Espectrometria Of Massa | Silva L.P.,University of Brasilia
Current Drug Targets | Year: 2014

Natural resources are widely used as raw materials by industries. In most cases, abundant byproducts with low economic interest are also generated from agro-industrial supply chains. There are several examples for the rational use of agro-industrial byproducts in the nanobiotechnology field aiming for the development of novel products and high value added processes. Such raw materials include carapaces, pelages, blood, bagasses, and straws. Molecules from such materials (e.g. chitosan, cellulose, and albumin) are used as scaffolds of unprecedented novel nanostructure. Research efforts comprising a combination of sustainability, nanobiotechnology, and nanomedicine have emerged. One major area in nano-biotechnological research of agro-industrial byproducts is represented by the field of drug delivery systems (DDS). Among the main advantages of agro-industrial byproducts used as drug carriers are their abundance; low price; high bio-compatibility; good biodegradability; moderate bioresorbability, associated with reduced systemic toxicity or even no tox-icity; and often bioactivity. The goal of these efforts includes not only the possibility to characterize and manipulate matter on the nanoscale, but also to develop sustainable products and processes, including the development of platforms for drug delivery aiming for the treatment of pathologies such as cancer and diabetes. Indeed, there is great hope that the use of agro-industrial byproducts in nanobiotechnology will increase not only agricultural and livestock productivity, but will also contribute to other areas such as the development of DDS with new properties and low production costs; and sustainable environmental management due to the reuse of industrial discharged byproducts. This review will compile current findings on the use of byproducts as building blocks for modern drug carrier systems, emphasizing the challenges and promising applications. © 2014 Bentham Science Publishers.


Ramada M.H.S.,University of Brasilia | Ramada M.H.S.,Laboratorio Of Espectrometria Of Massa | Steindorff A.S.,University of Brasilia | Bloch C.,Laboratorio Of Espectrometria Of Massa | Ulhoa C.J.,Federal University of Goais
Proteomics | Year: 2016

Trichoderma harzianum is a fungus well known for its potential as a biocontrol agent against many fungal phytopathogens. The aim of this study was to characterize the proteins secreted by T. harzianum ALL42 when its spores were inoculated and incubated for 48 h in culture media supplemented with glucose (GLU) or with cell walls from Fusarium solani (FSCW), a phytopathogen that causes severe losses in common bean and soy crops in Brazil, as well as other crop diseases around the world. Trichoderma harzianum was able to grow in Trichoderma Liquid Enzyme Production medium (TLE) and Minimal medium (MM) supplemented with FSCW and in TLE+GLU, but was unable to grow in MM+GLU medium. Protein quantification showed that TLE+FSCW and MM+FSCW had 45- and 30- fold, respectively, higher protein concentration on supernatant when compared to TLE+GLU, and this difference was observable on 2D gel electrophoresis (2DE). A total of 94 out of 105 proteins excised from 2DE maps were identified. The only protein observed in all three conditions was epl1. In the media supplemented with FSCW, different hydrolases such as chitinases, β-1,3-glucanases, glucoamylases, α-1,3-glucanases and proteases were identified, along with other proteins with no known functions in mycoparasitism, such as npp1 and cys. Trichoderma harzianum showed a complex and diverse arsenal of proteins that are secreted in response to the presence of FSCW, with novel proteins not previously described in mycoparasitic-related studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Silva L.P.,Laboratorio Of Espectrometria Of Massa
Animal Reproduction | Year: 2014

This review focus on the potential benefits, threats, and challenges of nanotechnology in animal reproduction. The investigation of gamete cells in high-resolution, production of nanobiosensors, and development of nanosystems aiming the sustained release of gonadotropins and steroid hormones are only some few examples of growing interest areas. Current facts and future prospects have highlighted the great potential of nanotechnology in reproduction field. Emerging concepts and technologies will be contextualized, reviewed, and explored in this review.


Barbosa E.F.,Laboratorio Of Espectrometria Of Massa | Barbosa E.F.,University of Brasilia | Silva L.P.,Laboratorio Of Espectrometria Of Massa | Silva L.P.,University of Brasilia
Surface and Interface Analysis | Year: 2013

A nanoscale characterization of modified and unmodified polypropylene (PP) microtubes internal surface was performed to investigate their structural, chemical, and physical properties. Nanoroughness, stiffness, elasticity, attraction behavior, adhesion forces, and chemical environment were investigated to test some manufacturer statements regarding Axygen MAXYMum Recovery® products. They announced that this class of material presented special features, originated from a modification to the original PP resin and by using a diamond polished mould, providing lower retention and minor interference on laboratorial tests, such as low roughness and little interaction tendency. Then, in this study, modified and control internal surfaces of PP microtubes were compared by atomic force microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Nanoroughness and force spectroscopy parameters assessed by atomic force microscopy showed out as a sensible and high-resolution technique, crucial to discriminate differences between the surfaces. This type of investigation can be considered as a promising approach that can be applied to other polymeric systems, considering nanoscale properties, physical/chemical modifications, and as an alternative route for quality control checking concerning polymeric surfaces. © 2013 John Wiley & Sons, Ltd.


Barbosa E.F.,Laboratorio Of Espectrometria Of Massa | Barbosa E.F.,University of Brasilia | Silva L.P.,Laboratorio Of Espectrometria Of Massa | Silva L.P.,University of Brasilia
Surface and Interface Analysis | Year: 2012

An alternative way for plastic tubes surface analysis was presented, and the time course of the effects of solvent exposure was evaluated. Atomic force microscopy was used to qualitatively and quantitatively analyze internal tubes topography. Differences in nanoroughness parameters were shown as potential markers for quality control check to detect differences among brands and areas along each tube. Mass spectrometry analysis was carried out to evaluate the effects of some solvents after the intrinsic contact with the polymer. The obtained spectra did not allow the visualization of any leaching component, suggesting a low rate of some possible reaction or dissociative interaction caused by polymer and tested solvent interactions that were in concordance with principal component analysis. The use of these techniques as tools for quality control evaluation, or search for new support to biomolecules immobilization can be seen as important innovations and can be applied in several other investigative and developmental approaches. © 2011 John Wiley & Sons, Ltd.


Oliveira N.B.,University of Brasilia | Schwartz C.A.,University of Brasilia | Bloch Jr. C.,Laboratorio Of Espectrometria Of Massa | Paulino L.,Laboratorio Of Espectrometria Of Massa | Pires Jr. O.R.,University of Brasilia
Bulletin of Environmental Contamination and Toxicology | Year: 2013

Three individuals of silver carp (Hypophthalmichthys molitrix) were collected biweekly from Paranoá Lake (DF, Brazil) for analysis of microcystin (MC) concentrations in their muscle and liver tissue. Analysis by high performance liquid chromatography and mass spectrometry revealed MC masses and fragmentation patterns that were identified as MC-LR (995.04 m/z), MC-LA (909.01 m/z) and an unknown MC (987.07 m/z). Concentrations were calculated as MC-LR equivalents using a calibration curve prepared with a standard of MC-LR. May/06 was the month with the highest MC-LR equivalent concentrations in muscle and liver (3.83 ± 2.78, and 12.94 ± 10.51 μg g-1, respectively). Our results show that during the drought months (April-September), consumption of fish with these MC concentrations would result in exposure to MCs that greatly exceed the World Health Organization's recommended tolerable daily intake limit of 0.04 μg MC kg-1 body weight. © 2012 Springer Science+Business Media New York.


PubMed | Federal University of Goais, Laboratorio Of Espectrometria Of Massa and University of Brasilia
Type: Journal Article | Journal: Proteomics | Year: 2016

Trichoderma harzianum is a fungus well known for its potential as a biocontrol agent against many fungal phytopathogens. The aim of this study was to characterize the proteins secreted by T. harzianum ALL42 when its spores were inoculated and incubated for 48 h in culture media supplemented with glucose (GLU) or with cell walls from Fusarium solani (FSCW), a phytopathogen that causes severe losses in common bean and soy crops in Brazil, as well as other crop diseases around the world. Trichoderma harzianum was able to grow in Trichoderma Liquid Enzyme Production medium (TLE) and Minimal medium (MM) supplemented with FSCW and in TLE+GLU, but was unable to grow in MM+GLU medium. Protein quantification showed that TLE+FSCW and MM+FSCW had 45- and 30- fold, respectively, higher protein concentration on supernatant when compared to TLE+GLU, and this difference was observable on 2D gel electrophoresis (2DE). A total of 94 out of 105 proteins excised from 2DE maps were identified. The only protein observed in all three conditions was epl1. In the media supplemented with FSCW, different hydrolases such as chitinases, -1,3-glucanases, glucoamylases, -1,3-glucanases and proteases were identified, along with other proteins with no known functions in mycoparasitism, such as npp1 and cys. Trichoderma harzianum showed a complex and diverse arsenal of proteins that are secreted in response to the presence of FSCW, with novel proteins not previously described in mycoparasitic-related studies.

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