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Zaqueo K.D.,Federal University of Rondonia | Kayano A.M.,Federal University of Rondonia | Domingos T.F.S.,Federal University of Fluminense | Moura L.A.,Federal University of Fluminense | And 13 more authors.
Comparative Biochemistry and Physiology -Part A : Molecular and Integrative Physiology

Snake venom toxins are related not only in detention, death and the promotion of initial digestion of prey but also due to their different biochemical, structural and pharmacological effects they can result in new drugs. Among these toxins snake venom serine proteases (SVSPs) should be highlighted because they are responsible for inducing changes in physiological functions such as blood coagulation, fibrinolysis, and platelet aggregation. This article presents the first serine protease (SP) isolated from Bothrops brazili: BbrzSP-32. The new SP showed 36 kDa of relative molecular mass and its absolute mass was confirmed by mass spectrometry as 32,520 Da. It presents 79.48% identity when compared to other SVSPs and was able to degrade the α-chain of fibrinogen, in in vitro models, because of this it is considered a SVTLE-A. It showed dose-dependent activity in the process of degradation of fibrin networks demonstrating greater specificity for this activity when compared to its thrombolytic action. BbrzSP-32 demonstrated proteolytic activity on gelatin and chromogenic substrates for serine proteases and thrombin-like enzymes (S-2288 and S-2238 respectively), besides having coagulant activity on human plasma. After pre-incubation with PMSF and benzamidine the coagulant and proteolytic activities on the S-2288 and S-2238 substrates were reduced. BbrzSP-32 shows stability against pH and temperature variations, demonstrating optimum activity between 30 and 40 °C and in the pH range 7.5 to 8.5. A new SP with potential biotechnological application was isolated. © 2016 Elsevier Inc. Source

McGugan J.R.,Harvard University | Byrd G.D.,Harvard University | Roland A.B.,Harvard University | Caty S.N.,Harvard University | And 6 more authors.
Journal of Chemical Ecology

Poison frogs sequester chemical defenses from arthropod prey, although the details of how arthropod diversity contributes to variation in poison frog toxins remains unclear. We characterized skin alkaloid profiles in the Little Devil poison frog, Oophaga sylvatica (Dendrobatidae), across three populations in northwestern Ecuador. Using gas chromatography/mass spectrometry, we identified histrionicotoxins, 3,5- and 5,8-disubstituted indolizidines, decahydroquinolines, and lehmizidines as the primary alkaloid toxins in these O. sylvatica populations. Frog skin alkaloid composition varied along a geographical gradient following population distribution in a principal component analysis. We also characterized diversity in arthropods isolated from frog stomach contents and confirmed that O. sylvatica specialize on ants and mites. To test the hypothesis that poison frog toxin variability reflects species and chemical diversity in arthropod prey, we (1) used sequencing of cytochrome oxidase 1 to identify individual prey specimens, and (2) used liquid chromatography/mass spectrometry to chemically profile consumed ants and mites. We identified 45 ants and 9 mites in frog stomachs, including several undescribed species. We also showed that chemical profiles of consumed ants and mites cluster by frog population, suggesting different frog populations have access to chemically distinct prey. Finally, by comparing chemical profiles of frog skin and isolated prey items, we traced the arthropod source of four poison frog alkaloids, including 3,5- and 5,8-disubstituted indolizidines and a lehmizidine alkaloid. Together, the data show that toxin variability in O. sylvatica reflects chemical diversity in arthropod prey. © 2016 Springer Science+Business Media New York Source

Proano-Bolanos C.,Queens University of Belfast | Zhou M.,Queens University of Belfast | Wang L.,Queens University of Belfast | Coloma L.A.,Centro Jambatu Of Investigacion Y Conservacion Of Anfibios | And 3 more authors.
Journal of Proteomics

Phyllomedusine frogs are an extraordinary source of biologically active peptides. At least 8 families of antimicrobial peptides have been reported in this frog clade, the dermaseptins being the most diverse. By a peptidomic approach, integrating molecular cloning, Edman degradation sequencing and tandem mass spectrometry, a new family of antimicrobial peptides has been identified in Cruziohyla calcarifer. These 15 novel antimicrobial peptides of 20-32 residues in length are named cruzioseptins. They are characterized by having a unique shared N-terminal sequence GFLD- and the sequence motifs -VALGAVSK- or -GKAAL(N/G/S) (V/A)V- in the middle of the peptide. Cruzioseptins have a broad spectrum of antimicrobial activity and low haemolytic effect. The most potent cruzioseptin was CZS-1 that had a MIC of 3.77 μM against the Gram positive bacterium, Staphylococcus aureus and the yeast Candida albicans. In contrast, CZS-1 was 3-fold less potent against the Gram negative bacterium, Escherichia coli (MIC 15.11 μM). CZS-1 reached 100% haemolysis at 120.87 μM. Skin secretions from unexplored species such as C. calcarifer continue to demonstrate the enormous molecular diversity hidden in the amphibian skin. Some of these novel peptides may provide lead structures for the development of a new class of antibiotics and antifungals of therapeutic use. Biological significance: Through the combination of molecular cloning, Edman degradation sequencing, tandem mass spectrometry and MALDI-TOF MS we have identified a new family of 15 antimicrobial peptides in the skin secretion of Cruziohyla calcarifer. The novel family is named "Cruzioseptins" and contains cationic amphipathic peptides of 20-32 residues. They have a broad range of antimicrobial activity that also includes effective antifungals with low haemolytic activity. Therefore, C. calcarifer has proven to be a rich source of novel peptides, which could become leading structures for the development of novel antibiotics and antifungals of clinical application. © 2016 Elsevier B.V. Source

The use of flies and other arthropods as evidence to estimate the time of death of a body in an advanced state of putrefaction, known as forensic entomology, an auxiliary discipline of forensic science. The presence of larvae on the human body lifeless, allows the forensic entomologist support the pathologist, establishing minimum time frames death since the arrival of the insects to the body until the moment of discovery. In this study, a list of Diptera of forensic importance collected in the vicinity of the hospital Adolfo Prince Lara, Puerto Cabello morgue are presented. In the months January to March 2012 were made three collections, one per month. Using 500 g of beef liver decomposed (in chromatics stage) the flies were taken temperature and relative humidity (mean = 30 and 48%, respectively). A total of 257 individuals corresponding to families Piophilidae (1.1%), Sarcophagidae (4.1%), Phoridae (10.2%), Muscidae (32.3%) and Calliphoridae (52.3%). However, the most representative species during sampling in the vicinity of the was L. cuprina, followed by C. megacephala. © 2016, Revista Salus. All rights reserved. Source

Galeano A.,National University of Colombia | Urrego L.E.,National University of Colombia | Sanchez M.,National University of Colombia | Penuela M.C.,University Regional Amazonica
Aquatic Botany

Mauritia flexuosa L.f. (swamp forest palm) stands are widely distributed in the poorly drained zones of flood plains and low terraces. They provide several economic and cultural resources for local human communities and play an important ecological role in Amazonia. To identify the main factors involved in the natural regeneration dynamics of M. flexuosa, we surveyed the recruitment, mortality, and survival rates of seedlings from June 2010 to November 2012 on a 1-ha plot in a flooded forest area of Colombian Amazonia. The recorded mortality and recruitment rates of M. flexuosa were higher compared to its survival rates over time. These three parameters, included in a CCA, were positively correlated to the basal area (BA) of M. flexuosa adults. The CCA the first two axes explained 88% of data variance. While recruitment was positively related to flooding levels, mortality was positively related to basal area of species other than M. flexuosa and to the lowest organic matter percentages in the topsoil. In a PCA first two axes explained 57% of variance and showed positive correlation of both basal area and seedling abundance of M. flexuosa to soil organic matter content, and to poorly drained soils. Pore water pH and percentages of sand and clay increased with improved soil drainage conditions. © 2015. Source

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