Navegando por Palavras-chave "Peptídeos Antimicrobianos"
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- ItemRestritoBioactive peptides in human milk: a systematic review(Universidade Federal de São Paulo, 2023-04-25) Laurito, Taís Fontellas [UNIFESP]; Tashima, Alexandre Keiji [UNIFESP]; Tomita, Luciana Yuki [UNIFESP]; http://lattes.cnpq.br/4118529511504082; http://lattes.cnpq.br/3395922547042342; http://lattes.cnpq.br/8349145426746162Objectives: Identify peptides and biological activity in human milk (HM). Methodology: A systematic review was conducted in the MEDLINE, LILACS, Cochrane, Embase) and from the gray literature (Google Scholar) (CRD42020202505). until August 2020. The keywords were “human milk”, “breast milk", “breast feeding”, “mothers milk”, “lactation”, “infant milk”, “lactation”, “bioactive peptides'' and “peptides''. Two independent researchers carried out searches in the databases, selections, extractions in blind. In case of disagreement, the third author checked the eligibility criteria. The inclusion criteria were: original article, written in English, Portuguese or Spanish, which utilized human-derived milk peptide, and tested its bioactivity through in vivo or in vitro assays. Results: A total of 1519 articles were located from databases and 30 were included from references of included articles. In the end, 37 articles were included. The most common peptide activities found in HM were antimicrobial, ACE, antioxidant, immunomodulatory, opioid activities and growth regulation. The majority of studies assessed peptides from β-caseins and lactoferrin. The methodological advances were important to find a higher number of peptides, especially after the development of soft ionization methods of macromolecules applied to mass spectrometry. Conclusion: Many peptides and its bioactivities were identified in human milk. Importance of breast feeding including those bioactive peptides properties can contribute to stimulating women and society to encourage a friendly environment for breastfeeding.
- ItemAcesso aberto (Open Access)Bioprospecção de Novos Peptídeos Antimicrobianos em Ovos de Galinha Gallus gallus domesticus(Universidade Federal de São Paulo (UNIFESP), 2019-07-25) Santos, Sandra Regina Dos [UNIFESP]; Miranda, Antonio De [UNIFESP]; Silva Jr, Pedro Ismael da [UNIFESP]; http://lattes.cnpq.br/7158586957386749; http://lattes.cnpq.br/1357848049935882; http://lattes.cnpq.br/6321614296807612; Universidade Federal de São Paulo (UNIFESP)A long time the eggs avian developed some defense systems for minimize the predatory animals, for example, desenvolviment a rigid limestone strutucture (shell). However for to success of the embryo the presence of molecular components there are related with nutrition of the embryo as the may also be associated with capacity to inhibit the growth and proliferation of the microorganisms present in the environment in where these eggs live. So, can these components have some biotechnological application or therapeutic, mainly focusing on the use against microorganisms with showed mechanisms of resistance to conventional antibiotics? This study aimed to evaluate the presence of bioactive molecules, focusing in antimicrobial peptides, in the extract of chicken eggs of the species Gallus gallus domesticus. For this was used the extract of chicken eggs without the shel of the specie Gallus gallus domesticus, after the steps of fractionation several fractions were obtained with antimicrobial potential against Micrococcus luteus A270 (bacterial Gram-positive) and Eschericchia coli D31 (bacterial Gram-negative), Aspergillus niger (filamentous fungus – isolated of the environment), Candida albicans MDM8 and Cryptococcus neoformans strain99 (yeasts). Two fractions obtained of the elution 80% acetonitrile were characterized, sequenced and submeted the solid phase peptide synthesis using strategy t-Boc. The peptide Ovoin, with sequence SVSTVLTSKYR and molecular weight 1240 Da was active against M.luteus and C. neoformans, but this sequence did not similarity in searches made database, could be a new antimicrobial peptide present in chicken eggs. And the peptide Ovipin, with sequence GYSFTTTAER and molecular weight 1131 D, was active against M. luteus, E. coli, A. niger e C. neoformans. The searches made in database was demonstrated that this sequence is a fragment of actin protein of the Gallus gallus domesticus.
- ItemAcesso aberto (Open Access)Estudos de síntese, conformação e atividade biológica da gomesina e análogos através de diferentes metodologias(Universidade Federal de São Paulo (UNIFESP), 2013) Domingues, Tatiana Moreira [UNIFESP]; Miranda, Antonio de [UNIFESP]; Riske, Karin do Amaral [UNIFESP]; http://lattes.cnpq.br/9178927522709552; http://lattes.cnpq.br/1357848049935882; Universidade Federal de São Paulo (UNIFESP)O peptideo antimicrobiano gomesina (Gm) foi inicialmente isolado da hemolinfa da Acanthoscurria gomesiana, uma aranha caranguejeira encontrada no Brasil. Fortemente cationico, possui 18 residuos de aminoacidos (pGlu1-Cys-Arg-Arg-Leu5-Cys-Tyr-Lys-Gln-Arg10-Cys-Val-Thr-Tyr-Cys15-Arg-Gly-Arg-NH2) e duas ligacoes de dissulfeto nas posicoes Cys2,15 e Cys6,11. Trata-se de um PAM de largo espectro de acao, cuja atividade litica foi avaliada como elevada e rapida. Gm e analogos foram sintetizados pelo metodo em fase solida e utilizando-se a estrategia t-Boc. Em seguida, os peptideos foram clivados, purificados e caracterizados, alcancando-se um indice de pureza satisfatorio. Por meio de ensaios biologicos (de atividade antimicrobiana e hemolitica), estudos espectroscopicos e de cinetica de vazamento de carboxifluoresceina (CF), a Gm e todos os seus analogos foram avaliados, tendo sido possivel tracar uma relacao estrutura/atividade para esses peptideos, que comprova a importancia da manutencao das ligacoes de dissulfeto pelos analogos da Gm para o desempenho de uma boa atividade litica. Com base nesses primeiros resultados, a Gm e seu analogo menos ativo ([Ser2,6,11,15]-Gm) foram selecionados para analises mais detalhadas, utilizando-se, para tanto, modelos de membrana. Assim sendo, bicamadas lipidicas (LUVs), micelas e monomeros de SDS (dodecil sulfato de sodio) foram os sistemas mimeticos escolhidos para investigar o mecanismo de acao desses peptideos. A analise dos dados de calorimetria de titulacao isotermica (ITC) e de cinetica de vazamento de CF indicou forte interacao da Gm com as LUVs e rapida acao de desestruturacao dessas bicamadas, em um processo entalpicamente dirigido. Atraves da utilizacao das tecnicas de espalhamento de luz estatico e dinamico, e microscopia otica de contraste de fase, foi possivel detectar a formacao de grandes agregados lipidicos, mesmo em baixas razoes peptideo/lipidio. Com o intuito de minimizar a agregacao lipidica, um lipidio modificado contendo o polimero polietilenoglicol (PE-PEG2000) foi adicionado as vesiculas. A Gm tambem apresentou intensa ligacao exotermica (ITC) e uma alta taxa de permeabilizacao dessas bicamadas modificadas, alem de reduzida formacao de agregados. O analogo [Ser2,6,11,15]-Gm exibiu semelhante atividade a da Gm em interacao com LUVs contendo 50 mol% de POPG e uma diminuicao acentuada dessa atividade para LUVs com 25 mol% de POPG, reafirmando a importancia da atracao eletrostatica para esses peptideos. Alem disso, espectros de CD confirmaram que a Gm e seu analogo linear adotam conformacao em dobra beta quando em contato com lipossomas e SDS acima e abaixo da CMC (concentracao micelar critica). Em outros estudos, analises de fluorescencia e absorbancia de analogos ciclicos da Gm, marcados com um residuo de Trp, em presenca de diferentes concentracoes de SDS, apontaram para uma maior interacao desses peptideos com o SDS monomerico, resultando em um maior blueshift do espectro de emissao do Trp, bem como em um aumento na absorbancia das amostras, maior ou igual ao causado pelo SDS na forma micelar. O uso de dois sistemas mimeticos de membrana diferentes, bem como as diversas metodologias empregadas, foi fundamental para uma ampla investigacao das etapas requeridas pela Gm para causar a ruptura das biomembranas. Alem disso, esses estudos foram importantes na deteccao e caracterizacao da formacao de agregados durante a interacao da Gm com moleculas anfifilicas anionicas, agregacao essa que possivelmente se estende a outros peptideos cationicos, e que muitas vezes e negligenciada.
- ItemSomente MetadadadosEstudos sinérgicos de peptídeos antimicrobianos na terapia fotodinâmica(Universidade Federal de São Paulo (UNIFESP), 2020-10-29) Moreira, Gustavo Magalhaes [UNIFESP]; Oliveira Junior, Vani Xavier De [UNIFESP]; Universidade Federal de São PauloObjective: The work proposes the peptides' synthesis with antimicrobial activities described, such as Aurein 1.2, Temporin L and Mastoparan L, to measure the synergistic effect together with hypericin as a photosensitizer in a non-toxic concentration to healthy cells. Methods: The solid-phase synthesis technique was chosen to obtain the peptides under study. Purification and characterization were performed by liquid chromatography coupled to electrospray ionization mass spectrometry, NanoDrop spectrophotometer, and Circular Dichroism. The hemolytic concentrations of each peptide, the enzymatic degradation at fetal bovine serum assay and the interaction to the generation of singlet oxygen by photosensitizer were verified for the biological assays. The peptides were tested individually performed at serial concentrations: 128 to 1 μmol L-1 , and together with hypericin at: 1, 10 and 100 μmol L-1. The best times for the photosensitizer internalization and light irradiation (595 nm) were defined for each microorganism. Results: The high helical content of the peptides was observed from the circular dichroism spectra analysis in TFE 60% and SDS at 20 mmol L-1. The hypericin internalization and irradiation times found were up to 30 min for the microorganisms tested. Peptide degradation was observed after 1 h. The peptides do not interfere with the singlet oxygen generation from hypericin. Temporin L was hemolytic above 16 μmol L-1, and below this concentration, it inhibited the Serratia marcenscens (ATCC 4112) and Candida tropicallis (IOC 4560) growth after combining the techniques. Mastoparan L showed a synergistic effect for Escherichia coli (SBS 363), Staphylococcus aureus (ATCC 29213), and C. glabrata (IOC 4565). Aurein 1.2, improved its activity for all microorganisms, except for S. marcenscens (ATCC 4112). Conclusions: The synergistic effect was observed for antimicrobial activity in vitro because the MIC values of the peptides were better when combined with photodynamic therapy.