Дисертації з теми "Antimicrobial peptid"
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Dannehl, Claudia. "Fragments of the human antimicrobial LL-37 and their interaction with model membranes." Phd thesis, Universität Potsdam, 2013. http://opus.kobv.de/ubp/volltexte/2013/6814/.
Повний текст джерелаAufgrund der steigenden Resistenzen von Zellstämmen gegen traditionelle Therapeutika sind alternative medizinische Behandlungsmöglichkeiten für bakterielle Infektionen und Krebs stark gefragt. Antimikrobielle Peptide (AMPs) sind Bestandteil der unspezifischen Immunabwehr und kommen in jedem Organismus vor. AMPs lagern sich von außen an die Zellmembran an und zerstören ihre Integrität. Das macht sie effizient und vor allem schnell in der Wirkung gegen Bakterien, Viren, Pilzen und sogar Krebszellen. Das Ziel dieser Arbeit lag in der physikalisch-chemischen Charakterisierung zweier Peptidfragmente die unterschiedliche biologische Aktivität aufweisen. Die Peptide LL-32 und LL-20 waren Teile des humanen LL-37 aus der Kathelizidin-Familie. LL-32 wies eine stärke Aktivität als das Mutterpeptid auf, während LL-20 kaum aktiv gegen die verschiedenen Zelltypen war. In dieser Arbeit wurde die Wechselwirkung der Peptide mit Zellmembranen systematisch anhand von zweidimensionalen Modellmembranen in dieser Arbeit untersucht. Dafür wurden Filmwaagenmessungen mit IR-spektroskopischen und Röntgenstreumethoden gekoppelt. Circulardichroismus-Spektroskopie im Volumen komplementierte die Ergebnisse. In der ersten Näherung wurde die Struktur der Peptide in Lösung mit der Struktur an der Wasser/Luft-Grenzfläche verglichen. In wässriger Lösung sind beide Peptidfragmente unstrukturiert, nehmen jedoch eine α-helikale Sekundärstruktur an, wenn sie an die Wasser/Luft-Grenzfläche adsorbiert sind. Das biologisch unwirksamere LL-20 bleibt dabei teilweise ungeordnet. Das steht im Zusammenhang mit einer geringeren Grenzflächenaktivität des Peptids. In der Zweiten Näherung wurden Versuche mit Lipidmonoschichten als biomimetisches Modell für die Wechselwirkung mit der Zellmembran durchgeführt. Es konnte gezeigt werden, dass sich die Peptide fluidisierend auf negativ geladene Dipalmitylphosphatidylglycerol (DPPG) Monoschichten auswirken, was einer Membranverdünnung an Bakterienzellen entspricht. Eine Interaktion der Peptide mit zwitterionischem Phosphatidylcholin (PC), das als Modell für Säugetierzellen verwendet wurde, konnte nicht klar beobachtet werden, obwohl biologische Experimente das hämolytische Verhalten zumindest von LL-32 zeigten. In der dritten Näherung wurde das Membranmodell näher an die Membran von humanen Erythrozyten angepasst, indem gemischte Monoschichten aus Sphingomyelin (SM) und PC hergestellt wurden. Die physikalisch-chemischen Eigenschaften der Lipidfilme wurden zunächst ausgearbeitet und anschließend der Einfluss der Peptide untersucht. Es konnte anhand verschiedener Versuche gezeigt werden, dass die Wechselwirkung von LL-32 mit der Modellmembran verstärkt ist, wenn eine Koexistenz von fluiden und Gelphasen auftritt. Zusätzlich wurde die Wechselwirkung der Peptide mit der Membran von Krebszellen imitiert, indem ein geringer Anteil negativ geladener Lipide in die Monoschicht eingebaut wurde. Das hatte allerdings keinen nachweislichen Effekt, so dass geschlussfolgert werden konnte, dass die hohe Aktivität von LL-32 gegen Krebszellen ihren Grund in der veränderten Fluidität der Membran hat und nicht in der veränderten Oberflächenladung. Darüber hinaus wurden Ähnlichkeiten zu Melittin, einem AMP aus dem Bienengift, dargelegt. Die Ergebnisse dieser Arbeit sprechen für einen Detergenzien-artigen Wirkmechanismus des Peptids LL-32 an der Zellmembran.
Das, Sanjit. "Methodological development in peptide chemistry for synthesis of antimicrobial and antifungal derivatives of marine natural peptides." Thesis, Perpignan, 2018. http://www.theses.fr/2018PERP0054.
Повний текст джерелаThe click chemistry has become indispensible in the many areas of chemistry associated with drug design. In this context, as we know the study concerning the impact of triazole insertion on the conformation of peptaibol is limited, we have conducted the study to investigate the impact and adaptability of the 1, 4-disubstituted 1, 2, 3-triazole insertion into different peptaibols. Depending on the outcome of this experiment relating to reduced activity and perturbed conformation of the peptaibol analogue, the dipeptide surrogate decorated with the triazole moiety bearing various hydrophobic substituents was inserted at the very N-ter part of the peptaibol. The improvement of the bioactivity and restoration of the conformation for the peptaibol analogues was observed and the fact was also supported by the results obtained from the biophysical study of the selected analogues of ALM F50/5. We have further extended our study to employ our strategy to be applied on the therapeutic P42 peptide which suffers from the limitation of lack of permeability and stability. P42 peptide is involved in the pathophysiology of neurodegenerative Huntington’s disease. A total of 12 analogues of P42-TAT peptide were synthesized through SPPS by our optimized protocol. In the second part, we have developed a strategy for synthesizing the cyclic lipopeptide originated from marine cynaobacterial species. Our main objective was to synthesize Hormothamnin A, a cyclic undecapeptide consisting of several unnatural amino acids including dehydroamino acid (Dhaa) which makes the synthesis of this peptide complicated. Due to this reason, firstly, we have chosen to apply our strategy to synthesize Trichormamide A, a relatively simpler kind of cylic lipopeptide. After accomplishing this task, a first attempt was made to synthesize Hormothamnin A. The preliminary result of this is presented in this section. At last, we have tried to develop a robust methodology to synthesize Fmoc-Dhaa in solution phase and its insertion into the peptaibol sequence through a standard SPPS protocol. The preliminary results we have got concerning the Dhaa synthesis and its insertion into peptaibol are also discussed here in addition with the solid phase synthesis of natural Bergofungin D
Weichbrodt, Conrad. "Elektrophysiologische Charakterisierung des mitochondrialen Porins VDAC1 und des antimikrobiellen Peptids Dermcidin in lösungsmittelfreien Modellmembranen." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2013. http://hdl.handle.net/11858/00-1735-0000-0001-BAA4-C.
Повний текст джерелаShyam, Radhe. "Cationic amphipathic peptoid oligomers as antimicrobial peptide mimics." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC048/document.
Повний текст джерелаLiving organisms produce antimicrobial peptides (AMPs) to protect themselves against microbes.The growing problem of antimicrobial resistance calls for new therapeutic strategies and the natural AMPs have shown ground-breaking potential to address that issue. They show broad-spectrum activity and their main mechanism of action by bacterial cell membrane disruption implies low emergence of resistance which makes them potent candidates for replacing conventional antibiotics. Nevertheless, few hurdles are impeding their use, notably poor bioavailability profile. Some of these limitations can be overcome by developing peptidomimetics of AMPs which exhibit antibacterial activities together with enhanced therapeutic potential. Peptoids (i.e. N-alkyl glycine oligomers) adopting cationic amphipathic helical structures are mostly competent AMP mimetics. From a conformational point of view, peptoids are fundamentally more flexible than peptides primarily due to the cis/trans isomerism of N,N-disubstituted amides but studies in this area have shown that cis amide conformation can be controlled by careful choice of side-chain to set a PolyProline I-type helical structure of peptoids. In this thesis, the genesis of novel amphipathic cationic peptoids carrying cis-directing tert-butyl and/or triazolium-type side-chains and their untapped potential to act against bacteria will be discussed comprehensively. First, the solutionphase synthesis of tert-butyl-based oligomers was developed. Second, novel method of solid-phase submonomer synthesis was optimised to access 1,2,3-triazolium-based oligomers. Then, the synthesised cationic oligomers were evaluated for their antibacterial potential, followed by antibiofilm activity and cell selectivity assays. In the end, to have insights on the mode of action of amphipathic peptoids, microscopy was carried out
Rolland, Jean-Luc. "Aspects moléculaires et biochimiques des stylicines, peptides multifonctionnels identifiés chez la crevette bleue du Pacifique Litopenaeus stylirostris (Crustacea, Decapoda)." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20049.
Повний текст джерелаThe work reported here was motivated by the economical importance of the pacific blue shrimp Litopenaeus stylirostris farming where high mortality rates are due to bacterial and viral diseases. It consists in the characterisation of two original peptides, the first members of a new multifunctional family of peptides from peneide shrimps, the stylicines. Those two peptides, named stylicines 1 and 2, are negatively charged (pI < 6.0), and characterised by a proline-rich N-terminal region and a C-terminal region containing 13 cysteine residues. Stylicines are synthesized by heamocytes where they are stored within small cytoplasmic granules. To understand the role of these peptides in the immune response of shrimps to a vibrio infection, their recombinant forms were produced in E. coli BL21 (DE3) plysS, purified and characterised. The two rstylicines display biological anti-proliferative and blood clotting activities. Only rstylicine 1 displays antimicrobial activities: antifungal against Fusarium oxysporum (MIC<2.5µM) and bacteriostatic against Gram (−) bacteria, Vibrio sp. (MIC<80µM). Moreover this peptide displays an LPS-binding activity (dissociation constant (Kd) of 9.6×10−8 M) and agglutinate Vibrio. penaeicida "in vitro". Finally, the presence of sequences coding for modified forms of stylicine 1 in some shrimp's genome may be in relation with their lower ability to survive infections
FASOLI, Anna. "Biophysical mechanisms of membrane perturbation and signal transduction produced by proteins and peptides." Doctoral thesis, Università degli studi di Ferrara, 2015. http://hdl.handle.net/11392/2388995.
Повний текст джерелаZerfas, Breanna L. "Creating Novel Antimicrobial Peptides: From Gramicidin A to Screening a Cyclic Peptide Library." Thesis, Boston College, 2017. http://hdl.handle.net/2345/bc-ir:107444.
Повний текст джерелаAs the threat of microbial resistance to antibiotics grows, we must turn in new directions to find new drugs effective against resistant infections. Antimicrobial peptides (AMPs) and host-defense peptides (HDPs) are a class of natural products that have been well-studied towards this goal, though very few have found success clinically. However, as there is much known about the behavior of these peptides, work has been done to manipulate their sequences and structures in the search for more drug-like properties. Additionally, novel sequences and structures mimicking those seen in nature have been discovered and characterized. Herein, we demonstrate our ability to finely tune the antimicrobial activity of various peptides, such that they can be provided with more clinically desirable characteristics. Our results show that gramicidin A (gA) can be made to be less toxic via incorporation of unnatural cationic amino acids. This is achieved by synthesizing lysine analogues with diverse hydrophobic groups alkylated to the side-chain amine. Through exploring different groups, we achieved peptide structures with improved selectivity for bacterial over mammalian membranes. Additionally, we were able to achieve novel broad-spectrum gram-negative activity for gA peptides. In efforts to combat bacterial resistance to cationic antimicrobial peptides (CAMPs), we have directed our reported amine-targeting iminoboronate chemistry towards neutralizing Lys-PG in bacterial membranes. Originally incorporating 2-APBA into gA, we found this to hinder the peptide’s activity. However, we were successful in increasing the potency of gA3R, a cationic mutant of gA, towards S. aureus by using a co-treatment of this peptide with a Lys-PG binding structure. Currently, we are exploring this strategy further. Finally, we describe our work towards establishing a novel cyclic peptide library incorporating a 2-APBA warhead for iminoboronate formation with a given target. In this, we have achieved intermolecular reduction of iminoboronates, strengthening the stringency of library screening. Although we were unsuccessful in finding a potent hit for binding of the lipid II stem peptide, screening against human transferrin yielded selective hits. Currently we are investigating these hits to understand their activity and therapeutic potential
Thesis (PhD) — Boston College, 2017
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
Borrelli, Alexander P. "Synthetic Genes for Antimicrobial Peptides." Digital WPI, 2003. https://digitalcommons.wpi.edu/etd-theses/427.
Повний текст джерелаJodoin, Joelle. "Histone H5: Bioinspiration for Novel Antimicrobial Peptides." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36976.
Повний текст джерелаLinser, Sebastian. "Development of new antimicrobial peptides based on the synthetic peptide NK-2." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=982021631.
Повний текст джерелаKwok, Hoi-shan, and 郭凱珊. "The comparison of biological properties of L- and D-enantiomeric antimicrobial peptides." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206507.
Повний текст джерелаpublished_or_final_version
Pharmacology and Pharmacy
Master
Master of Medical Sciences
Nicolás, Lorenzón Esteban [UNESP]. "Efeito do comprimento e da polaridade do espaçador entre cadeias do peptídeo Hylina-C na forma dimérica." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/88051.
Повний текст джерелаCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Neste trabalho foi avaliado o efeito da dimerização e do comprimento/polaridade do espaçador utilizado na formação dos dímeros, na estrutura e atividade biológica do peptídeo antimicrobiano: Gly-Trp-Leu-Asp-Val-Ala-Lys-Lys-Ile-Gly-Lys-Ala-Ala-Phe-Asn-Val-Ala-Lys-Asn-Phe-Leu-CONH2. Nesse sentido, o monômero e três dímeros com diferentes espaçadores foram sintetizados pelo método de síntese de peptídeo em fase sólida (SPFS) utilizando uma combinação das químicas Fmoc e Boc. Análises por cromatografia de fase reversa e espectrometria de massas confirmaram o sucesso das sínteses e das purificações. Os ensaios de atividade antimicrobiana, em termos de CIM mostraram que a dimerização não aumentou a capacidade do peptídeo de inibir o crescimento de bactérias e fungos. No entanto, quando analisada a capacidade dos peptídeos de matar E. coli, um menor tempo para produzir o efeito inibitório foi observado para os dímeros. Adicionalmente, a atividade hemolítica dos peptídeos também foi avaliada, encontrando-se um aumento significativo, aproximadamente 40 vezes, para os dímeros em relação ao monômero. Com o objetivo de tentar explicar esses efeitos, o teste de proteção osmótica foi realizado. No entanto, o tamanho dos poros foi semelhante, o que não permite explicar as diferenças em termos desta variável. Conhecendo seus diâmetros, foi possível determinar que o poro é formado por 6 moléculas monoméricas ou 3 diméricas. Estudos de permeabilização mostraram que a porcentagem e a velocidade de liberação de carboxifluoresceína foram maiores para os dímeros quando comparados com o monômero, especialmente em vesículas contendo esfingomielina. Este ensaio também mostrou que a duplicação da concentração de monômeros não é suficiente para atingir a capacidade de permeabilização dos dímeros, confirmando que a proximidade das cadeias é um fator...
This work analyzed the effect of dimerization and the length/polarity of the spacer used in the formation of dimers, in the structure and biological activity of the antimicrobial peptide: Gly-Trp-Leu-Asp-Val-Ala-Lys-Lys-Ile-Gly-Lys-Ala-Ala-Phe-Asn-Val-Ala-Lys-Asn-Phe-Leu-CONH2. In this way, the monomer and three dimers (Lys-branched) with different spacer groups were synthesized by solid phase peptide synthesis methodology using a combination of Fmoc and Boc chemical approaches. Analysis by reverse phase chromatography and mass spectrometry confirmed the success of the synthesis and purifications. The antimicrobial activity assay, in terms of MICs showed that dimerization did not increase the ability of the peptides to inhibit the growth of bacteria and fungi. Nevertheless, when analyzing the peptides activity against E. coli in terms of kinetics, an increased velocity was observed for the dimers. The hemolytic activity of peptides was also evaluated, finding a very significant difference, approximately 40 times greater for dimers. Aiming to explain this difference, the osmotic protection test was performed, but the pore size was similar, which can not explain the differences in terms of this variable. Knowing the diameter of the pores, it was possible to determine that the pore is formed by six monomeric or three dimeric molecules. Additionally, permeabilization studies showed that the percentage and rate of carboxyfluorescein release were larger for the dimers compared with monomer, especially in vesicles containing sphingomyelin. This test also showed that the use of two times more monomer concentration´s is not sufficient to reach dimers permeabilization capacity, confirming that the proximity of the chains is an important factor in the activity of this peptide. Analysis by circular dichroism revealed that peptides in aqueous solution are in random coil, whereas... (Complete abstract click electronic access below)
Ringstad, Lovisa. "Interaction Between Antimicrobial Peptides and Phospholipid Membranes Effects of Peptide Length and Composition /." Doctoral thesis, Uppsala : Acta Universitatis Upsaliensis, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-101989.
Повний текст джерелаGomes, von Borowski Rafael. "Obtention et évaluation de l’activité antibiofilm de peptides et peptidomimétiques issus de Capsicum baccatum var. pendulum (Solanaceae)." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1B005.
Повний текст джерелаBiofilm confers to bacteria many benefits due to the production of a matrix that improves their resistance and tolerance to antibiotics. Staphylococcus epidermidis is one of the most important clinical bacteria, able to form biofilm on medical devices such as pacemakers, urinary catheters and prostheses. In this context, peptides have been proposed as an important alternative as a treatment or as anti-infective surface agents. This study focuses on the identification of new antibiofilm natural and synthetic peptides from the Capsicum baccatum var. pendulum pepper. As a result, a lead peptide responsible for the antibiofilm activity against S. epidermidis was selected and extensively studied. It acts by a new mechanism of action that we call "matrix anti-assembly" (MAA). In the first chapter, we explore the link between peptides, pathogenic biofilms and the antibiofilm activity. Chapter 2 consists of the main experimental results of this thesis. It describes the antibiofilm characterization of the lead peptide acting by the AAM new mechanism of action, independent of cell regulation. Cytotoxicity tests are also presented. These results allowed us to patent this peptide, referenced in Chapter 3. The last chapter presents the possible use of antibiofilm peptidomimetics as a perspective. The strategy is to create small peptide-like molecules. These peptidomimetics retain the inherent capabilities of the lead peptide, but are more resistant to proteases and / or more active
O biofilme apresenta vários benefícios às bactérias devido à existência de uma matriz que confere resistência e tolerância aos antibioticos. O Staphylococcus epidermidis é uma das bactérias com maior relevância clínica devido à sua capacidade de formar biofilmes em dispositivos médicos, tais como, marca-passos, cateteres urinários e próteses. Neste contexto, os peptídeos têm sido propostos como uma alternativa importante, tanto como tratamento, quanto como agentes anti-infecciosos de superfície. Este estudo consiste na identificação de novos peptídeos naturais e sintéticos, derivados da pimenta Capsicum baccatum var. pendulum, com atividade antibiofilme. Por conseguinte, foi selecionado e estudado extensivamente um peptídeo de referência que apresentou a melhor atividade antibiofilme contra S. epidermidis. Este peptídeo atua através de um novo mecanismo de ação que descrevemos e chamamos de "anti-montagem de matriz" (AMM). No primeiro capítulo deste trabalho foi abordado a ligação entre peptídeos, biofilmes patogênicos e a atividade antibiofilme. O Capítulo 2 consiste nos principais resultados experimentais desta tese como a caracterização da atividade antibiofilme do peptídeo de referência, que age através do novo mecanismo de ação AMM independente da regulação celular e os testes de citotoxicidade. Esses resultados nos permitiram patentear o peptídeo em questão, referenciado no Capítulo 3. Finalmente, o último capítulo descreve o possível uso de peptidomiméticos antibiofilme como uma perspectiva. A estratégia é criar pequenas moléculas semelhantes ao peptídeo de referência. Estes peptidomiméticos mantêm as capacidades inerentes ao peptídeo principal, porém são mais resistentes a proteases e / ou mais ativos
Strauss, Joshua. "Investigating bacterial lipopolysaccharides and interactions with antimicrobial peptides." Worcester, Mass. : Worcester Polytechnic Institute, 2009. http://www.wpi.edu/Pubs/ETD/Available/etd-012009-120216/.
Повний текст джерелаWan, Yang. "Synthesis of β,γ-diamino acids and their use to design new analogues of the antimicrobial peptide Gramicidin Septide antimicrobien, la Gramicidine S". Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS407/document.
Повний текст джерелаIn our group, we are interested in developing peptides containing β,γ-diamino acids . Along with many other peptides containing unnatural amino acids, they have shown the ability to possess stable conformations and/or interesting biological activities. Moreover, those peptides are usually more resistant to proteolysis. In order to synthesize stereopure γ-amino acids, we have developed a synthetic route using Blaise reaction and subsequent diastereoselective reduction as key reactions. Through applying this method, we have synthesized β,γ-diamino acids derived from D-phenylalanine and L-glutamic acid. The former β,γ-diamino acid was used for designing antimicrobial peptide gramicidin S analogues. Compared with mother molecule, the analogues exerted much less host cell cytotoxicity while remaining interesting antibacterial activity. Meanwhile, it gave us more knowledge for further developing analogues of gramicidin S as well as other antimicrobial peptides. We also paid lots of effort to efficiently synthesize cyclic β,γ-diamino acids starting from L-glutamic acid. Interestingly, when oligomers incorporating this β,γ-diamino acids and α-amino acids, they have shown the potential to adopt stable conformations. The following studies will be continuously investigated
DAMIANO, Maria Alessandra. "Ulteriori evidenze di attività antimicrobiche in invertebrati marini." Doctoral thesis, Università degli Studi di Palermo, 2014. http://hdl.handle.net/10447/92564.
Повний текст джерелаVila, Farrés Xavier. "Development of new antimicrobial peptides and peptidomimetics and mechanism of resistance to peptide antibiotics." Doctoral thesis, Universitat de Barcelona, 2014. http://hdl.handle.net/10803/285375.
Повний текст джерелаActualment al mon hi ha un greu problema derivat de dos factors relacionats, el primer factor es el increment de la resistència, especialment del bacteris del grup ESKAPE. El segon factor es la disminució dràstica en el nombre d’antibiòtics aprovats per la FDA. Aquests dos problemes fan que hi hagi una urgència per trobar nous antimicrobians efectius en front d’aquestes soques resistents. En aquesta tesi hem abordat dos temes diferents però que estan relacionats a la hora de trobar nous antibiòtics. El primer tema abordat es el de conèixer a fons els mecanismes de resistència de certs antibiòtics, en aquest cas peptídics, en front diferents tipus de soques tant Gram-positives (S. mitis) com Gram-negatives (A. nosocomialis). Els dos antibiòtics peptídics pels que s’ha estudiat la resistència son daptomicina i colistina, en front de S. mitis i A. nosocomialis respectivament. Ambdós pèptids actuen a nivell de membrana, per tant ens centrarem en veure les modificacions produïdes en els soques resistents. Per part de S. mitis resistent a daptomicina, es pot veure una sobreexpressió de dues proteïnes que tenen dominis homòlegs amb altres proteïnes involucrades en la resistència a daptomicina en altres bacteris. En la resistència a colistina es pot apreciar com les soques resistents d’A. nosocomialis presenten una deficiència del LPS. També hem proposat diferents alternatives com a nous antibiòtics, en aquest cas en front de soques A. baumannii. Dos tipus d’aproximacions van ser utilitzades, la primera, i mes clàssica es la de trobar nous antimicrobians, vàrem trobar mastoparan i va diferents paràmetres van ser optimitzat però sense obtindré bons resultats in vivo. També es van provar diferents pèptids provinents de les secrecions de les granotes, presentant bona activitat en front soques d’Acinetobacter, i per últim, les ceragenines, anàlegs del àcid cólic, que tenen bona activitat en front de totes les soques tant colistina sensibles com colistina resistents en Gram-negatius. La segona aproximació es buscant pèptids capaços d’inhibir l’adherència entre el bacteri i la cèl•lula del hoste bloquejant l’acció de la proteïna OmpA. S’ha trobat un pèptid amb bona activitat fins i tot in vivo.
HORA, Gabriel Costa Alverni da. "Simulações computacionais do peptídeo híbrido Plantaricina-Pediocina em membranas fosfolipídicas puras e binárias compostas por POPC: POPG." Universidade Federal de Pernambuco, 2016. https://repositorio.ufpe.br/handle/123456789/18337.
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CNPq
Peptídeos antimicrobianos são componentes importantes do sistema de defesa de diversos organismos contra possíveis invasores. Em geral, são pequenos (até 100 aminoácidos), catiônicos e anfipáticos. Eles têm despertado o interesse da comunidade científica por sua capacidade de atuação contra micróbios, que não conseguem desenvolver resistência a esses peptídeos. Ou seja, eles emergem como complemento e/ou alternativa ao uso dos antibióticos convencionais. Este trabalho desenvolveu um modelo computacional de um peptídeo híbrido de pediocina A (N-terminal) e plantaricina 149a (C-terminal), dois peptídeos bactericidas. Dados experimentais obtidos pelo grupo da prof. Dra. Rosângela Itri do IFUSP foram utilizados para modelagem e comparação dos resultados. Foram feitas simulações de MD do peptídeo interagindo com membranas puras e mistas de POPC e POPG utilizando os parâmetros do campo de força GROMOS 53A6 e 54A7. As simulações com uma unidade do peptídeo revelaram a atualização 54A7 era a mais adequado para modelagem desses sistemas. Os mapas de estrutura secundária mostraram que o peptídeo adquire configuração mais ordenada quando interage com membranas com maior quantidade de POPG em sua composição. As simulações com duas unidades do peptídeo sugeririam que o peptídeo interage e penetra na camada de POPG através da região Cterminal. Na simulação com membrana de POPC, nenhuma das porções terminais ficou estável no interior da membrana. O efeito do aumento da concentração de peptídeos foi examinado colocando cinco e dez unidades do peptídeo para interagir com as membranas. Na membrana de POPC, os peptídeos não formam um único aglomerado e causam pouca perturbação na bicamada. Já na membrana de POPG, o efeito da interação do aglomerado de peptídeos é acentuado, provocando grandes deformações na bicamada lipídica, praticamente a destruindo. Esse fenômeno sugere um possível mecanismo carpete para ação do peptídeo sobre a membrana fosfolipídica de bactérias.
Antimicrobial peptides are important components of defense system in various organizations against possible invaders. They are generally small (100 aminoacids), cationic and amphipathic. They have stimulated the interest of the scientific community for its ability to act against microbes that cannot develop resistance to these peptides. That is, they emerge as complement and/or alternative to the use of conventional antibiotics. This study developed a computational model of a hybrid peptide pediocin A (Nterminal) and plantaricin 149a (C-terminal), two bactericidal peptides. Experimental data obtained by the group of prof. Dr. Rosângela Itri (IFUSP) were used for modeling and compare the results. MD simulations were made of the peptide interacting with pure and mixed POPC and POPG membranes. These simulations were performed using the parameters of the force field GROMOS 53A6 and 54A7. Simulations with a single copy of the peptide revealed that the force field 54A7 was the most appropriate for modeling these systems. The secondary structure maps showed that the peptide acquires a more ordered configuration when interacting with membranes with higher amounts of POPG in its composition. The simulations with two copies of the peptide suggest that the peptide interacts and penetrates the POPG layer via the C-terminal part. In the simulation with POPC membrane, none of the end portions remained stable within the membrane. The effect of increasing the peptide concentration of was examined by placing five and ten copies of the peptide to interact with the membranes. In the POPC membrane, the peptides do not form a single cluster and they cause little disturbance in the bilayer. In the POPG membrane, the interaction of peptides cluster is enhanced, causing large deformation and practically destroying the lipid bilayer. This phenomenon suggests a possible carpet mechanism of action of the peptide on the phospholipid membrane of bacteria.
Bagheri, Mojtaba [Verfasser]. "Cationic antimicrobial peptides : thermodynamic characterization of peptide-lipid interactions and biological efficacy of surface-tethered peptides / Mojtaba Bagheri." Berlin : Freie Universität Berlin, 2010. http://d-nb.info/1025126971/34.
Повний текст джерелаLorenzón, Esteban Nicolás. "Efeito do comprimento e da polaridade do espaçador entre cadeias do peptídeo Hylina-C na forma dimérica /." Araraquara : [s.n.], 2011. http://hdl.handle.net/11449/88051.
Повний текст джерелаBanca: Ana Marisa Fusco Almeida
Banca: Vani Xavier de Oliveira Júnior
Resumo: Neste trabalho foi avaliado o efeito da dimerização e do comprimento/polaridade do espaçador utilizado na formação dos dímeros, na estrutura e atividade biológica do peptídeo antimicrobiano: Gly-Trp-Leu-Asp-Val-Ala-Lys-Lys-Ile-Gly-Lys-Ala-Ala-Phe-Asn-Val-Ala-Lys-Asn-Phe-Leu-CONH2. Nesse sentido, o monômero e três dímeros com diferentes espaçadores foram sintetizados pelo método de síntese de peptídeo em fase sólida (SPFS) utilizando uma combinação das químicas Fmoc e Boc. Análises por cromatografia de fase reversa e espectrometria de massas confirmaram o sucesso das sínteses e das purificações. Os ensaios de atividade antimicrobiana, em termos de CIM mostraram que a dimerização não aumentou a capacidade do peptídeo de inibir o crescimento de bactérias e fungos. No entanto, quando analisada a capacidade dos peptídeos de matar E. coli, um menor tempo para produzir o efeito inibitório foi observado para os dímeros. Adicionalmente, a atividade hemolítica dos peptídeos também foi avaliada, encontrando-se um aumento significativo, aproximadamente 40 vezes, para os dímeros em relação ao monômero. Com o objetivo de tentar explicar esses efeitos, o teste de proteção osmótica foi realizado. No entanto, o tamanho dos poros foi semelhante, o que não permite explicar as diferenças em termos desta variável. Conhecendo seus diâmetros, foi possível determinar que o poro é formado por 6 moléculas monoméricas ou 3 diméricas. Estudos de permeabilização mostraram que a porcentagem e a velocidade de liberação de carboxifluoresceína foram maiores para os dímeros quando comparados com o monômero, especialmente em vesículas contendo esfingomielina. Este ensaio também mostrou que a duplicação da concentração de monômeros não é suficiente para atingir a capacidade de permeabilização dos dímeros, confirmando que a proximidade das cadeias é um fator... (Resumo completo clicar acesso eletrônico abaixo)
Abstract: This work analyzed the effect of dimerization and the length/polarity of the spacer used in the formation of dimers, in the structure and biological activity of the antimicrobial peptide: Gly-Trp-Leu-Asp-Val-Ala-Lys-Lys-Ile-Gly-Lys-Ala-Ala-Phe-Asn-Val-Ala-Lys-Asn-Phe-Leu-CONH2. In this way, the monomer and three dimers (Lys-branched) with different spacer groups were synthesized by solid phase peptide synthesis methodology using a combination of Fmoc and Boc chemical approaches. Analysis by reverse phase chromatography and mass spectrometry confirmed the success of the synthesis and purifications. The antimicrobial activity assay, in terms of MICs showed that dimerization did not increase the ability of the peptides to inhibit the growth of bacteria and fungi. Nevertheless, when analyzing the peptides activity against E. coli in terms of kinetics, an increased velocity was observed for the dimers. The hemolytic activity of peptides was also evaluated, finding a very significant difference, approximately 40 times greater for dimers. Aiming to explain this difference, the osmotic protection test was performed, but the pore size was similar, which can not explain the differences in terms of this variable. Knowing the diameter of the pores, it was possible to determine that the pore is formed by six monomeric or three dimeric molecules. Additionally, permeabilization studies showed that the percentage and rate of carboxyfluorescein release were larger for the dimers compared with monomer, especially in vesicles containing sphingomyelin. This test also showed that the use of two times more monomer concentration's is not sufficient to reach dimers permeabilization capacity, confirming that the proximity of the chains is an important factor in the activity of this peptide. Analysis by circular dichroism revealed that peptides in aqueous solution are in random coil, whereas... (Complete abstract click electronic access below)
Mestre
Morin, Kimberly M. "Cloning and expression of plasmids encoding multimers of antimicrobial peptides indolicidin and PGQ." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0425103-153311.
Повний текст джерелаBell, Stephanie. "Antimicrobial peptide gene expression in human tonsils." Thesis, University of Newcastle upon Tyne, 2009. http://hdl.handle.net/10443/3589.
Повний текст джерелаBorelli, Alexander P. "Synthetic genes for antimicrobial peptides." Link to electronic thesis, 2003. http://www.wpi.edu/Pubs/ETD/Available/etd-0428103-102059/.
Повний текст джерелаFranzman, Michael Ryan. "Targeted antimicrobial activity of SMAP28 conjugated to IgG antibody." Thesis, University of Iowa, 2007. http://ir.uiowa.edu/etd/140.
Повний текст джерелаBergsson, Gudmundur. "Antimicrobial polypeptides and lipids as a part of innate defense mechanism of fish and human fetus /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-546-1/.
Повний текст джерелаErikson, Alexander K. "Antimicrobial Peptide Development: From Massively Parallel Peptide Sequencing to Bioinformatic Motif Identification." BYU ScholarsArchive, 2020. https://scholarsarchive.byu.edu/etd/8761.
Повний текст джерелаFrohm, Nilsson Margareta. "The human antimicrobial peptide hCAP18 in epithelial defense /." Stockholm : [Karolinska institutets bibl.], 2001. http://diss.kib.ki.se/2001/91-7349-029-6/.
Повний текст джерелаWu, Manhong. "Characterization of bactenecin, a small antimicrobial cationic peptide." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0002/NQ39006.pdf.
Повний текст джерелаEl, Abbouni Sarah. "Microencapsulation of LL-37 Antimicrobial Peptide in PLGA." Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/235.
Повний текст джерелаNilebäck, Linnea. "Recombinant spider silk with antimicrobial properties." Thesis, Linköpings universitet, Institutionen för fysik, kemi och biologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-102804.
Повний текст джерелаTollin, Maria. "Antimicrobial peptides and proteins in innate immunity : emphasis on isolation, characterization and gene regulation /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-270-5/.
Повний текст джерелаLópez, Marcos Alejandro Sulca. "Desenvolvimento de novos peptídeos antimicrobianos a partir de proteínas dos venenos das serpentes peruana Bothrops pictus e Bothriopsis oligolepis." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-11042017-083735/.
Повний текст джерелаResistance to antibiotics obtained by pathogenic microorganisms is a global health problem, so the search for new antimicrobial agents has been encouraged. Knowing that many protein fragments and analogues are bioactive peptides, the aim of this work was to develop new antimicrobial peptides (AMPs) based on the amino acid sequences and 3D structures of proteins apparently involved in the antimicrobial activity of snake venoms very little or not studied so far. The first steps taken were: a) selection of a phospholipase A2 (PLA2) present in the venom from a Peruvian Bothrops sp. belonging to the family Viperidae, whose amino acid sequence was known, to model by homology its 3D structure; b) detection of antimicrobial activity in venoms from other Peruvian Viperidae Bothrops and Bothriopsis snakes, selection of an active venom, fractionation of it for isolation of proteins possibly involved in the antimicrobial activity, trypsinization of the isolated proteins, sequencing of the tryptic fragments for protein identification, location of such fragments in the amino acid sequences and 3D structures of proteins directly related in class, function and natural source to the isolated proteins. Then, peptide fragments from the chosen PLA2 (item a) and from the isolated proteins (item b) that presented structural features found in the known AMPs were selected and/or their analogues were designed. Finally, synthesis, purification and characterization of the peptides with AMP potential, (viii) verification on whether or not they display antimicrobial activity. The 3D-structure models of Bothrops pictus PLA2 and four amidated peptides (PLA2-1 to -4) derived from it were obtained, being PLA2-1 active against Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa as well as the yeasts Candida albicans, Candida krusei and Candida parapsilosis (MICs de 6.25-200 µmol.mL-1). Among the three Peruvian snake venoms tested Bothrops taeniatta, Bothrops barnetti and Bothriopsis oligolepis, the last two inhibited the growth of S. aureus (MICs 0.78-50 µmol.mL-1) and B. oligolepis presented a wide spectrum of bacterial action. Sequential fractionation followed by S. aureus growth inhibition assays of the main fractions led to active relatively homogeneous ones. Their trypsinization and sequencing of the tryptic fragments indicated that they contained metalloproteinases type III, serine-proteinase or lectins type CTL. Enzymatic activity and blood coagulation assays confirmed the nature of the isolated proteins. From the three amidated peptides (Bo-Ser1, Bo-Met1 e Bo-Lec1) derived from them, Bo-Met1 showed to be active against C. albicans, C. krusei e C. parapsilosis (MIC 6,25 - 200 µmol.mL-1). In summary, for the first time, it was demonstrated that: a) the venoms of the Peruvian snakes B. barnetti and B. oligolepis display antimicrobial activity, being the last of wide spectrum of action, b) the proteins isolated from B. oligolepis snake venom, including a serine-peptidase, are involved in the antimicrobial activity of the B. oligolepis snake venom, c) the amino acid sequences and 3D structures of acidic PLA2 and of other proteins found in the venoms of the Peruvian B. pictus e Bothriopsis oligolepis snakes can be used as safe and natural sources for the development of new AMPs potent against microorganisms of clinical and scientific interest.
Vargues, Thomas. "Antimicrobial peptides : structure, function and resistance." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4076.
Повний текст джерелаZhao, Hongxia. "Mode of action of antimicrobial peptides." Helsinki : University of Helsinki, 2003. http://ethesis.helsinki.fi/julkaisut/laa/biola/vk/zhao/.
Повний текст джерелаParisi, Rosaura. "Computational design of new antimicrobial peptides." Doctoral thesis, Universita degli studi di Salerno, 2018. http://hdl.handle.net/10556/3018.
Повний текст джерелаAntimicrobial peptides (AMP) are evolutionarily conserved components of the innate immune system. They have a broad spectrum of action against bacteria, fungi and viruses. Therefore, AMP are studied as probable substitutes of the traditional antibiotics, for which most pathogens have developed resistance. The main objective of this work was the design of novel linear peptides capable to interact with the cellular membrane of the common pathogens. In this work, sequences of active AMP were carefully obtained from the scientific literature and collected in Yadamp (http://yadamp.unisa.it/), a database of AMP created recently in the laboratory where this project was carried out. In Yadamp, there are information about peptides name, amino acid sequence, length, presence of disulfide bridges, date of discovery, activity and taxonomy. The most relevant chemical-physical properties are also listed. This database is mainly focused on the peptides activities. Experimental MIC values (the lowest concentration of an antimicrobial that inhibits the visible growth of a microorganism) are constantly obtained from careful reading the original papers. In this work, a great contribution was made in the enrichment of the database. In fact, 1009 sequences were added to Yadamp. It currently contains 3142 AMP sequences. For these AMP, 573 molecular descriptors were calculated. In addition, this project also involved the search for new molecular descriptors. Yadamp is a resource for QSAR investigations on AMP. It allows to create subsets of AMP, homogeneous in one, two or more parameters...[abstract by Author]
XXX ciclo
Arranz, Trullén Javier. "Unveiling the multifaceted antimicrobial mechanism of action of human host defence RNases." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/400666.
Повний текст джерелаThe present doctoral thesis is integrated into the large-scale study of the structure and function of human antimicrobial ribonucleases. These cationic and low molecular weight proteins are grouped into the ribonuclease A superfamily, considered one of the best characterized enzymes of the twentieth century. The RNase A superfamily is specific for vertebrates and has attracted remarkable interest due to the diversity of displayed biological properties; and represents an excellent example of a multifunctional protein´s family. Together with the main enzymatic activity we must highlight other biological properties such as the angiogenic, immunomodulatory and antimicrobial activities. The reported antimicrobial activity of distantly related family members in early vertebrates suggests that the family arouse with an ancestral function in host defence. Besides, the expression of several human RNases has been reported to be induced by infection. In particular, the RNases studied in this work, the human RNases 3, 6 and 7, are mainly expressed in eosinophils, monocytes and epithelial cells respectively. These proteins show a high cationicity due to the high proportion of basic residues and a remarkable antimicrobial activity against a wide range of human pathogens. Our research group has a consolidated experience in the study of the mechanism of action of human ribonucleases and the experimental work presented in this thesis is contributing to this overall research project. The main results achieved by the present PhD study are outlined below: - The characterization of the antimicrobial mechanism of RNase 6, both in bacteria cell cultures and using membrane models. Results highlight that the antimicrobial and cell agglutinating activities are mainly located at the N-terminus. - The resolution of the first three-dimensional structure of ribonuclease 6, obtained at 1.72 Å, which has set the structural basis for future functional studies. The kinetic characterization of RNase 6 mutant variants and the prediction of protein- substrate complexes have identified the enzyme nucleotide binding sites. - The study of the intracellular activity of ribonucleases 3, 6 and 7 and their derived Nterminal peptides against intracellular resident mycobacteria using a macrophage infected model. - The analysis of the anti-pathogenic mechanism of action of human antimicrobial proteins and peptides in mycobacterial infections and their applied therapies. - The comparative characterization of the antimicrobial mechanism of action of human RNases and their N-terminal derived peptides towards Candida albicans, as an eukaryote pathogen model. The results presented in this thesis will contribute to the understanding of the role of human RNases in the immune system and provide the structure- function basis to expand the initial project into the design of novel peptide mimetic therapeutics agents towards the eradication of resistant infectious diseases.
Giffard, Catriona Julie. "The structure-function relations of the antimicrobial peptide nisin." Thesis, University of York, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.319449.
Повний текст джерелаHammi, Ikram. "Isolement et caractérisation de bactériocines produites par des souches de bactéries lactiques isolées à partir de produits fermentés marocains et de différentes variétés de fromages français." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAF028/document.
Повний текст джерелаBacteriocins are antimicrobial peptides produced by bacteria naturally immunized against their own bacteriocins. This work has allowed the identification of several strains which produce antimicrobial peptides. These have been purified using different chromatographic techniques. Then, they have been identified and characterized by the measurement of their mass and by the analysis of their structure (proteomic approach/ Edman sequencing). Among the obtained results, there was:- the discovery of a new bacteriocin (maltaricin CPN) produced by C. maltaromaticum and belonging to the class IIa ;- the identification of three new pediocin PA-1 producing species;- the isolation of bacterial strains wich produce multiple bacteriocins belonging to several classes ;- the in vitro determination of a strong antimicrobial activity(affecting pathogens) with some bacteriocins.This work is still underway with the application of two bacteriocin producing strains in fermented milk (Lben) in order to tackle L. monocytogenes
Okechuku, Adaora. "Determination of the mode of action of the antibacterial peptide ApoEdp." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/determination-of-the-mode-of-action-of-the-antibacterial-peptide-apoedp(1937bcc4-f28b-416e-8dd7-8d493082ac2a).html.
Повний текст джерелаDíaz, i. Cirac Anna. "Mechanism of action of cyclic antimicrobial peptides." Doctoral thesis, Universitat de Girona, 2011. http://hdl.handle.net/10803/38252.
Повний текст джерелаAquesta tesi doctoral resulta de la combinació d’estudis mitjançant tècniques experimentals i computacionals amb l’objectiu d’entendre el mecanisme d’acció de "de novo" decapèptids cíclics amb elevada activitat antimicrobiana. Experimentalment, es va avaluar la influència de la substitució dels residus de fenilalanina per triptòfan en la seva activitat antimicrobiana i també la seva estabilitat sèrum humà, per tal de valorar la seva possible aplicació terapèutica envers el càncer. Per altra banda, es va simular la interacció del pèptid BPC194 c(KKLKKFKKLQ), millor candidat de la biblioteca de pèptids cíclics, amb models aniònics de bicapa lipídica. Els resultats van posar en manifest una relació estructura-funció derivada de la conformació estable dels pèptids que participen directament en la permeabilització de la membrana. Es va procedir doncs al disseny racional de nous pèptids cíclics sent el pèptid BPC490 el que va presentar una millor activitat bacteriana en comparació amb el pèptid més actiu de la llibreria original.
Bunkóczi, Gábor. "Structure determination of peptides with antimicrobial action." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=974033650.
Повний текст джерелаLu, Shanshan. "Immobilization of antimicrobial peptides onto titanium surfaces." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/12622.
Повний текст джерелаNeville, Frances Clare. "Interaction of antimicrobial peptides with bacterial membranes." Thesis, University of Leeds, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439597.
Повний текст джерелаChau, Tanguy. "Delivery, design, and mechanism of antimicrobial peptides." Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62063.
Повний текст джерелаCataloged from PDF version of thesis.
Includes bibliographical references.
Each year, 2 million people contract hospital-acquired bacterial infections, which causes the death of 100,000 patients and costs the US healthcare system over $21 billion. These infections have become dangerously resistant to our existing line of antibiotics and are rapidly spreading outside of hospitals and into communities. As molecular targets to develop new antibiotics are becoming exhausted, clinicians and scientist are concerned that antibiotic resistant infections will wipe out most of the major health benefits acquired over the last century. The work described in this thesis develops new antimicrobials strategies against bacterial infections, focusing on antimicrobial peptides (AmPs). We first delivered genes inducing the toxic expression of AmPs and other lytic agents directly into bacteria using re-engineered bacteriophages. Expression of these lytic agents in lysogenic bacteriophages resulted in bactericidal activity, and demonstrated, for the first time, a long-term cidal effect for over 20 hours. We then enhanced the efficacy of our approach by expressing the same agents in lytic bacteriophage, which resulted in complete suppression of the bacterial culture and prevented bacterial regrowth and resistance to bacteriophages. Since a large fraction of medical infections originates at the surface of implantable devices, we developed film coatings that release active AmPs to cover these surfaces and prevent bacterial colonization. We incorporated AmPs in layer-by-layer films and demonstrated that the kinetics of AmP release can be adjusted. These released AmPs still actively prevented bacterial growth and remained non-toxic towards mammalian cells. While natural AmPs have broad activity against pathogens, they are not optimized for a specific antimicrobial function or bacterial target. Thus, researchers have tried for decades to design highly active and specific de novo AmPs. One approach is to design new peptides using conserved motifs identified from the amino acid sequence of natural AmPs. We improved this approach by measuring the antimicrobial activity of a large database of natural AmPs and incorporating this activity information in the design algorithm. This strategy improved the success rate of designing de novo peptides from 45% to 73% and increased the antimicrobial strength of the designed peptides. Finally, we developed new potentiating strategies by studying the mode-of-action of the family of ponericin AmPs. First, we measured their cidal behavior and differentiated bactericidal ponericins from bacteriostatic ones. Using a modified AFM and a microfluidic device, we observed that the action of AmPs led to cellular death through the corrugation of bacterial, while subpopulation of cells resisted the action of the AmPs longer than others. Focusing on the ponericin G1 AmP, we correlated these visual observations with various membrane stress sensing mechanisms. We concluded that bacteria's ability to develop resistance to ponericin G1 requires the sensing and repair of misfolded membrane proteins via the CpxAR system, as well as DNA repair via induction of the SOS response by RecA. Using microarrarys, we showed that ponericin G1 targets tRNA synthetases in the ribosome. Finally, we demonstrated 99.999% killing of antibiotic resistant bacteria by potentiating ponericin G1 with the ribosomal antibiotic kanamycin, whereas no killing is observed when these two agents are applied independently. untreta The PhDCEP capstone requirement finalizes the work of this thesis by analyzing market entry and expansion strategies for an antimicrobial company commercializing genetically engineered bacteriophages. In conclusion, this thesis establishes new advances in the delivery, the design and the potentiation of AmPs in order to eradicate resilient bacterial infections.
by Tanguy Chau.
Ph.D.
Bolt, Hannah Louise. "Antimicrobial peptoids : design, synthesis and biological applications." Thesis, Durham University, 2016. http://etheses.dur.ac.uk/11947/.
Повний текст джерелаSOLLAMI, DELEKTA SZYMON. "Hexosomes as Drug Delivery Vehicles for Antimicrobial Peptides." Thesis, KTH, Skolan för kemivetenskap (CHE), 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-172360.
Повний текст джерелаOliveras, Rovira Àngel. "Síntesi de lipopèptids i de pèptids conjugats derivats de BP100. Caracterització estructural de lipopèptids lineals i cíclics." Doctoral thesis, Universitat de Girona, 2020. http://hdl.handle.net/10803/671194.
Повний текст джерелаActualment, es calcula que, aproximadament, un terç de la producció agrícola es perd a causa dels danys provocats per les plagues, resultant en un impacte econòmic molt important. Al voltant d’un terç d’aquestes pèrdues són provocades per fitopatògens. Avui en dia, la solució a aquests problemes es centra en l’ús de pesticides, fonamentalment derivats de coure, antibiòtics o fungicides; tanmateix, tot i ser eficaços, són altament contaminants. A més, els antibiòtics no estan permesos en molts països, perquè un ús abusiu provoca l’aparició ràpida de soques bacterianes resistents. La manca de tractaments no contaminants i efectius per al control de malalties de plantes ha motivat la recerca de nous compostos. Els pèptids antimicrobians són una de les alternatives més prometedores als pesticides tradicionals, perquè mostren una activitat biològica elevada. Per aquest motiu, en aquesta tesi doctoral es va plantejar el disseny, la síntesi i la caracterització de derivats de BP100
Raghoonanan, Venisha. "Molecular characterization and in vitro functional analysis of putative immunoprotective molecules in the soft tick, Ornithodoros savignyi." Diss., University of Pretoria, 2010. http://hdl.handle.net/2263/29182.
Повний текст джерелаDissertation (MSc)--University of Pretoria, 2010.
Biochemistry
unrestricted
Gooderham, William James. "Regulation of virulence and antimicrobial peptide resistance in Pseudomonas aeruginosa." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/1014.
Повний текст джерела