Gene expression analysis by ESTs sequencing of the Brazilian frog Phyllomedusa nordestina skin glands

AbstractThe subfamily Phyllomedusinae has attracted a great interest of many researchers mainly due to the high diversity of these frog species and plethora of pharmacological activities frequently observed for their skin secretions. Despite of this fact, mainly for new species, limited information is available regarding the molecular composition of these skin secretions and the cellular components involved in their production. Phyllomedusa nordestina is a recently described Brazilian frog species also popularly known as ‘tree-frogs’. Aiming at contributing to the biological knowledge of this species, we show here the gene expression profile of this frog skin secretion using a global ESTs analysis of a cDNA library. The marked aspect of this analysis revealed a significant higher transcriptional level of the opioid peptide dermorphins in P. nordestina skin secretion than in Phyllomedusa hypochondrialis, which is its closest related species, belonging both to the same phylogenetic group. Precursors of bioactive peptides as dermaseptins, phylloseptins, tryptophyllins, and bradykinin-like peptideswere also found in this library. Transcripts encoding proteins related to ordinary cellular functions and pathways were also described. Some of them are chiefly involved in the production of the skin secretion. Taken together, the data reported here constitute a contribution to the characterization of the molecular diversity of gene-encoded polypeptides with potential possibility of pharmacological exploitation. The transcriptional composition of the skin secretion may also help to give the necessary support for the definition of P. nordestina as a new species, which actually relies basically on frog morphological characteristics and geographical distribution

Effect of crotamine, a cell-penetrating peptide, on blastocyst production and gene expression of in vitro fertilized bovine embryos.

Made available in DSpace on 2015-03-06T10:29:29Z (GMT). No. of bitstreams: 1 Cnpgl2014ZygoteEffectofcrotamine.pdf: 409383 bytes, checksum: d2225aa35a48dc4200a05127e91eab4f (MD5) Previous issue date: 2015-03-04201

Marine biotechnology in Brazil : recent developments and its potential for innovation

Marine biotechnology is an emerging field in Brazil and includes the exploration of marine microbial products, aquaculture, omics, isolation of biologically active compounds, identification of biosynthetic gene clusters from symbiotic microorganisms, investigation of invertebrate diseases caused by potentially pathogenic marine microbes, and development of antifouling compounds. Furthermore, the field also encompasses description of new biological niches, current threats, preservation strategies as well as its biotechnological potential. Finally, it is important to depict some of the major approaches and tools being employed to such end. To address the challenges of marine biotechnology, the Brazilian government, through the Ministry of Science, Technology, Innovation, and Communication, has established the National Research Network in Marine Biotechnology (BiotecMar) (www.biotecmar.sage.coppe.ufrj.br). Its main objective is to harness marine biodiversity and develop the marine bioeconomy through innovative research

Molecular characterization of the interaction of crotamine-derived nucleolar targeting peptides with lipid membranes

A novel class of cell-penetrating, nucleolar-targeting peptides (NrTPs), was recently developed from the rattlesnake venom toxin crotamine. Based on the intrinsic fluorescence of tyrosine or tryptophan residues, the partition of NrTPs and crotamine to membranes with variable lipid compositions was studied. Partition coefficient values (in the 10(2)-10(5) range) followed essentially the compositional trend POPC:POPG≤POPG<POPC≤POPC:cholesterol. Leakage assays showed that NrTPs induce minimal lipid vesicle disruption. Fluorescence quenching of NrTPs, either by acrylamide or lipophilic probes, revealed that NrTPs are buried in the lipid bilayer only for negatively-charged membranes. Adoption of partial secondary structure by the NrTPs upon interaction with POPC and POPG vesicles was demonstrated by circular dichroism. Translocation studies were conducted using a novel methodology, based on the confocal microscopy imaging of giant multilamellar vesicles or giant multivesicular liposomes. With this new procedure, which can now be used to evaluate the membrane translocation ability of other molecules, it was demonstrated that NrTPs are able to cross lipid membranes even in the absence of a receptor or transmembrane gradient. Altogether, these results indicate that NrTPs interact with lipid bilayers and can penetrate cells via different entry mechanisms, reinforcing the applicability of this class of peptide as therapeutic tools for the delivery of molecular cargoes.This work was funded by the Portuguese Ministry of Education and Science (Fundação para a Ciência e a Tecnologia, FCT-MEC; including M.R. and A.S. fellowships SFRH/BD/37432/2007 and SFRH/BPD/26821/2006, respectively), the Spanish Ministry of Economy and Competitiveness (MINECO, grant SAF2011-24899), Generalitat de Catalunya (2009 SGR 492), FP7-PEOPLE IRSES (International Research Staff Exchange Scheme) project MEMPEPACROSS (European Union), and the European Biophysical Societies’ Association (EBSA)

Selective membrane interactions of nucleolar-targeting peptides

Copyright ©2010 the European Peptide SocietyPartial funding and M.R. PhD grant (SFRH/BD/37432/2007) by Portuguese Ministry of Science (FCTMCTES) and by Spanish Ministry of Science and Innovation (MICINN, grant BIO2008-04487–CO3) are acknowledge

Ion-exchange chromatography used to isolate a spermadhesin-related protein from domestic goat (Capra hircus) seminal plasma.

Made available in DSpace on 2018-06-06T01:01:05Z (GMT). No. of bitstreams: 1 ID278701.pdf: 688017 bytes, checksum: d1e9cd1f8a3c6a2ff0059e4a30bec727 (MD5) Previous issue date: 2007-01-16bitstream/item/178113/1/ID-27870-1.pd

Structural Dissection of Crotalicidin, a Rattlesnake Venom Cathelicidin, Retrieves a Fragment with Antimicrobial and Antitumor Activity

In silico dissection of crotalicidin (Ctn), a cathelicidin from a South American pit viper, yielded fragments Ctn[1-14] and Ctn[15-34], which were tested to ascertain to what extent they reproduced the structure and activity of the parent peptide. NMR data showing Ctn to be α-helical at the N-terminus and unstructured at the C-terminus were matched by similar data from the fragments. The peptides were tested against Gram-positive and -negative bacteria and for toxicity against both tumor and healthy cells. Despite its amphipathic α-helical structure, Ctn[1-14] was totally inert toward bacteria or eukaryotic cells. In contrast, unstructured Ctn[15-34] replicated the activity of parent Ctn against Gram-negative bacteria and tumor cells while being significantly less toxic toward eukaryotic cells. This selectivity for bacteria and tumor cells, plus a stability to serum well above that of Ctn, portrays Ctn[15-34] as an appealing candidate for further development as an anti-infective or antitumor lead.Research at Federal University of Ceará was supported by the Brazilian National Council for Scientific and Technological Development (CNPq), by the Ministry of Science and Technology, and by the Coordination for the Improvement of Higher Education Personnel (CAPES). Research at Pompeu Fabra University was supported by the Spanish Ministry of Economy and Competitiveness (MINECO, Grant SAF 2011-24899) and by Generalitat de Catalunya (Grant SGR2009-00492). Research at the Instituto de Química Física Rocasolano (IQFR-CSIC) was supported by MINECO (Project CTQ2011-22514; Grant FPI BES-2012-057717 to H.Z.-C.). We thank Prof. Jordi Vila, Servei de Microbiologia, Hospital Clínic, Universitat de Barcelona, for antimicrobial assays. Mobility support from the European Commission, Marie Curie Actions, International Research Staff Exchange Scheme (No. 247513, MEMPEPACROSS), is gratefully acknowledged.Peer Reviewe

Crotacetin, a novel snake venom C-type lectin, is homolog of convulxin

Snake venom (sv) C-type lectins encompass a group of hemorrhagic toxins, which are able to interfere with hemostasis. They share significant similarity in their primary structures with C-type lectins of other animals, and also present a conserved carbohydrate recognition domain (CRD). A very well studied sv C-type lectin is the heterodimeric toxin, convulxin (CVX), from the venoms of South American rattlesnakes, Crotalus durissus terrificus and C. d. cascavella. It consists of two subunits, alfa (CVXalpha , 13.9 kDa) and beta (CVXbeta , 12.6 kDa), joined by inter and intra-chain disulfide bounds, and is arranged in a tetrameric alpha4beta4 conformation. Convulxin is able to activate platelet and induce their aggregation by acting via p62/GPVI collagen receptor. Several cDNA precursors, homolog of CVX subunits, were cloned by PCR homology screening. As determined by computational analysis, one of them, named crotacetin beta subunit, was predicted as a polypeptide with a tridimensional conformation very similar to other subunits of convulxin-like snake toxins. Crotacetin was purified from C. durissus venoms by gel permeation and reverse phase high performance liquid chromatography. The heterodimeric crotacetin is expressed in the venoms of several C. durissus subspecies, but it is prevalent in the venom of C. durissus cascavella. As inferred from homology modeling, crotacetin induces platelet aggregation but noticeably exhibits antimicrobial activity against Gram-positive and Gram-negative bacteria

Ion-exchange chromatography used to isolate a spermadhesin-related protein from domestic goat (Capra hircus) seminal plasma.

Made available in DSpace on 2018-06-06T01:01:05Z (GMT). No. of bitstreams: 1 ID278701.pdf: 688017 bytes, checksum: d1e9cd1f8a3c6a2ff0059e4a30bec727 (MD5) Previous issue date: 2007-01-16bitstream/item/178113/1/ID-27870-1.pd