Navegando por Palavras-chave "peptidomics"

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    Caracterização proteômica, peptidômica e transcriptômica dos venenos de aranhas do gênero acanthoscurria
    (Universidade Federal de São Paulo (UNIFESP), 2015-04-09) Abreu, Thiago Ferreira de [UNIFESP]; Tashima, Alexandre Keiji Tashima [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Spiders are one of the most successful animals on the planet, currently recording 45,330 species divided into 3957 genus and separated in two suborders: Mesothelae and Opistothelae. The most studied spiders belong to the second suborder, which are organized in two groups based on chelicerae position (Araneomorph and Mygalomorphae) and are studied, among other reasons, because of their medical and biological relevance. The chelicerae inoculates a toxic secretion produced by the venom gland for subduying preys and protection against predators. The venom presents a range of components with specific functions and synergical effects. Recent studies of spider venoms demonstrated the presence of proteins and peptides with antimicrobial activity against fungi, bacteria and protozoa, ion channel modulation and selective activity against vertebrate and invertebrate receptors, indicating the biotechnological potential for these molecules. The study of the spider venom molecular arsenal is also relevant to the understanding of phylogeny and evolutionary success and to determine variations in composition, which may depend on individual variability, sexual dimorfism and diet. Nonetheless, there are few studies about these animals. In this study, considering the biotechnological potential and the biological relevance of the toxins in spider venoms, a quantitative proteomic study of venoms from male and female spiders belonging to Acanthoscurria gomesiana and Acanthoscurria juruenicola species was developed, besides transcriptomics of A. juruenicola venom glands, and antimicrobial assays of purified peptides. Transcriptomic analysis of female A. juruenicola venom glands resulted in 88,335 protein sequences obtained by translation of its respective cDNAs. Digestion of venoms with trypsin and thermolysin followed by mass spectrometry analysis by data-dependent acquisition (DDA) and data-independent acquisition (DIA) approaches resulted in the identification of 353 proteins in A. juruenicola venoms and 188 proteins in A. gomesiana venoms by automated de novo sequencing and database searches. Absolute quantification of proteins present in A. juruenicola spider venoms by DIA showed a prevalence of toxins, such as cysteine-rich venom protease (CRISPs), theraphotoxins, metalloendopeptidases, lipases, hyaluronidases, tyrosine-phosphatase and metallocarboxypeptidases. One of A. juruenicola theraphotoxins showed complete homology with the peptide already described from Acanthoscurria paulensis venom (U1-theraphotoxin-Ap1a) and a new theraphotoxin from A. gomesiana, Ag1a, was fully characterized. Crude venom fractionation by gel filtration chromatography in order to purify peptides (1-7 kDa) was accomplished, enabling the isolation and characterization of A. gomesiana and A. juruenicola theraphotoxins. Antimicrobial assays against a yeast (Candida albicans) and three bacteria, two Gram negatives (Pseudomonas aeruginosa and Escherichia coli) and one Gram positive (Micrococcus luteus) was accomplished with these peptides and the minimum inhibitory concentrations (MIC) were determined.
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    Caracterização proteômica, peptidômica e transcriptômica dos venenos de aranhas do gênero acanthoscurria
    (Universidade Federal de São Paulo (UNIFESP), 2015-04-09) Abreu, Thiago Ferreira de [UNIFESP]; Tashima, Alexandre Keiji Tashima [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Spiders are one of the most successful animals on the planet, currently recording 45,330 species divided into 3957 genus and separated in two suborders: Mesothelae and Opistothelae. The most studied spiders belong to the second suborder, which are organiz
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    Peptidomic Analysis of Human Cell Lines
    (Amer Chemical Soc, 2011-04-01) Gelman, Julia S.; Sironi, Juan; Castro, Leandro M. [UNIFESP]; Ferro, Emer S.; Fricker, Lloyd D.; Albert Einstein Coll Med; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Peptides have been proposed to function in intracellular signaling within the cytosol. Although cytosolic peptides are considered to be highly unstable, a large number of peptides have been detected in mouse brain and other biological samples. in the present study, we evaluated the peptidome of three diverse cell lines: SH-SY5Y, MCF7, and HEIC293 cells. A comparison of the peptidomes revealed considerable overlap in the identity of the peptides found in each cell line. the majority of the observed peptides are not derived from the most abundant or least stable proteins in the cell, and approximately half of the cellular peptides correspond to the N- or C- termini of the precursor proteins. Cleavage site analysis revealed a preference for hydrophobic residues in the PI position. Quantitative peptidomic analysis indicated that the levels of most cellular peptides are not altered in response to elevated intracellular calcium, suggesting that calpain is not responsible for their production. the similarity of the peptidomes of the three cell lines and the lack of correlation with the predicted cellular degradome implies the selective formation or retention of these peptides, consistent with the hypothesis that they are functional in the cells.