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Journal articles on the topic 'Antimicrobial peptid'

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Published: 1 April 2023

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1

Burgettiné Böszörményi, Erzsébet, István Barcs, Gyula Domján, Katalin Bélafiné Bakó, András Fodor, László Makrai, and Dávid Vozik. "A Xenorhabdus budapestensis entomopatogén baktérium sejtmentes fermentlevének és tisztítottfehérje-frakciójának antimikrobiális hatása néhány zoonoticus baktériumra." Orvosi Hetilap 156, no. 44 (November 2015): 1782–86. http://dx.doi.org/10.1556/650.2015.30274.

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Introduction: Many multi-resistant patogens appear continuously resulting in a permanent need for the development of novel antibiotics. A large number of antibiotics introduced in clinical and veterinary practices are not effective. Antibacterial peptides with unusual mode of action may represent a promising option against multi-resistant pathogens. The entomopathogenic Xenorhabdus budapestensis bacteria produce several different antimicrobial peptides compounds such as bicornutin-A and fabclavin. Aim: The aim of the authors was to evaluate the in vitro antibacterial effect of Xenorhabdus budapestensis using zoonotic patogen bacteria. Method: Cell-free conditioned media and purified peptide fractions of Xenorhabdus budapestensis were tested on Gram-positive (Rhodococcus equi, Erysipelothrix rhusiopathia, Staphylococcus aureus, Streptococcus equi, Corynebacterium pseudotuberculosis, Listeria monocytagenes) and Gram-negative bacteria (Salmonella gallinarum, Salmonella derbi, Bordatella bronchoseptica, Escherichia coli, Pasteurella multocida, Aeromonas hydrophila) using agar diffusion test on blood agar plates. Results: It was found that Xenorhabdus budapestensis bacteria produced compounds with strong and dose-dependent effects on the tested organisms. Purified peptid fraction exerted a more marked effect than cell free conditioned media. Gram-positive bacteria were more sensitive to this antibacterial effect than Gram-negative bacteria. Conclusions: Antibacterial peptide compound from Xenorhabdus budapestensis exert marked antibacterial effect on zoonotic patogen bacteria and they should be further evaluated in future for their potential use in the control or prevention of zoonoses. Orv. Hetil., 2015, 156(44), 1782–1786.
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Almsned, Fahad. "Designing Antimicrobial Peptide: Current Status." Journal of Medical Science And clinical Research 05, no. 03 (March 26, 2016): 19282–94. http://dx.doi.org/10.18535/jmscr/v5i3.153.

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Browne, Katrina, Sudip Chakraborty, Renxun Chen, Mark DP Willcox, David StClair Black, William R. Walsh, and Naresh Kumar. "A New Era of Antibiotics: The Clinical Potential of Antimicrobial Peptides." International Journal of Molecular Sciences 21, no. 19 (September 24, 2020): 7047. http://dx.doi.org/10.3390/ijms21197047.

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Antimicrobial resistance is a multifaceted crisis, imposing a serious threat to global health. The traditional antibiotic pipeline has been exhausted, prompting research into alternate antimicrobial strategies. Inspired by nature, antimicrobial peptides are rapidly gaining attention for their clinical potential as they present distinct advantages over traditional antibiotics. Antimicrobial peptides are found in all forms of life and demonstrate a pivotal role in the innate immune system. Many antimicrobial peptides are evolutionarily conserved, with limited propensity for resistance. Additionally, chemical modifications to the peptide backbone can be used to improve biological activity and stability and reduce toxicity. This review details the therapeutic potential of peptide-based antimicrobials, as well as the challenges needed to overcome in order for clinical translation. We explore the proposed mechanisms of activity, design of synthetic biomimics, and how this novel class of antimicrobial compound may address the need for effective antibiotics. Finally, we discuss commercially available peptide-based antimicrobials and antimicrobial peptides in clinical trials.
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Artuković Nadinić, Irena, Vladimir Mrljak, Marija Lipar, Marina Pavlak, Ljiljana Bedrica, and Renata Barić Rafaj. "The peptide hormone hepcidin." Veterinarska stanica 51, no. 2 (March 27, 2020): 187–98. http://dx.doi.org/10.46419/vs.51.2.9.

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Hepcidin je peptidni hormon i glavni je re- gulator metabolizma željeza. Otkriven je u humanom serumu i urinu 2000. godine i nazvan je LEAP-1 (engl. Liver Expressed Antimicrobial Protein). Nedugo nakon toga znanstvenici su pod vodstvom Tomasa Ganze u potrazi za antimikrobnim peptidima otkrili peptid povezan s upalom i nazvali ga “hepcidin”. Otkrili su da se sintetizira u jetri i da ima antimikrobna svojstva. Najveći broj istraživanja o djelovanju i regulaciji izlučivanja hepcidina učinjen je na mišjim modelima kada je ustanovljeno da se sinteza i izlučivanje hepcidina u miševa povećava u stanjima s povišenim količinama željeza u serumu i upalnim stanjima. Određivanje hepcidina u krvi i ostalim tjelesnim tekućinama određuje se imunološkim testovima s antihepcidinskim protutijelima - ELISA (prema engl. enzyme-linked immunosorbent assay) i masenom spektrometrijom. Koncentracije hepcidina u serumu određene masenom spektometrijom i koncentracije određene ELISA metodom dobro koreliraju. Imunološki testovi najtočnije mjere niske vrijednosti hepcidina, a masena spektrometrija točnije mjeri aktivnu formu hepcidina. Poremećaji u ekspresiji hepcidina javljaju se kod mnogih bolesti kao što su: anemija prouzročena kroničnim sistemskim bolestima, sideropenične anemije, maligne bolesti, hereditarne hemokromatoze i stanja s neefektivnom eritropoezom. Stoga mjerenje koncentracije hepcidina ima veliko značenje u dijagnostici i liječenju stanja u kojima je narušena ravnoteža željeza u organizmu. Napredak u razumijevanju uloge hepcidina u kontroli homeostaze željeza dovodi do novih mogućnosti liječenja u stanjima sa sniženim ili povišenim razinama željeza u organizmu. Hepcidin je nedavno identificiran kao akutno fazni protein s antimikrobnom i regulatornom funkcijom željeza. Mnogi su istra- živači pokazali interes za razvoj dijagnostičkog testa za mjerenje hepcidina u pasa. Ciljevi njihovog istraživanja bili su kloniranje i sekvenciranje gena psećeg hepcidina i prikupljanje preliminarnih podataka o pojavi hepcidina u pasa. Filogenetska analiza pokazala je da je humani hepcidin bio sličniji hepcidinu pasa nego hepcidinu glodavaca. U pasa, kao i u ljudi, hepcidin se najviše sinetitiza u jetri, a nešto slabije u bubrezima i plućnom tkivu pasa. Rezultat ovog istraživanja uspostavio je osnovu za buduća istraživanja psećeg hepcidina. Autori navode da psi mogu biti dobar model za istraživanje uloge hepcidina u ljudi.
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Chongsiriwatana, Nathaniel P., Tyler M. Miller, Modi Wetzler, Sergei Vakulenko, Amy J. Karlsson, Sean P. Palecek, Shahriar Mobashery, and Annelise E. Barron. "Short Alkylated Peptoid Mimics of Antimicrobial Lipopeptides." Antimicrobial Agents and Chemotherapy 55, no. 1 (October 18, 2010): 417–20. http://dx.doi.org/10.1128/aac.01080-10.

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ABSTRACTWe report the creation of alkylated poly-N-substituted glycine (peptoid) mimics of antimicrobial lipopeptides with alkyl tails ranging from 5 to 13 carbons. In several cases, alkylation significantly improved the selectivity of the peptoids with no loss in antimicrobial potency. Using this technique, we synthesized an antimicrobial peptoid only 5 monomers in length with selective, broad-spectrum antimicrobial activity as potent as previously reported dodecameric peptoids and the antimicrobial peptide pexiganan.
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Haney, Evan F., Leonard T. Nguyen, David J. Schibli, and Hans J. Vogel. "Design of a novel tryptophan-rich membrane-active antimicrobial peptide from the membrane-proximal region of the HIV glycoprotein, gp41." Beilstein Journal of Organic Chemistry 8 (July 24, 2012): 1172–84. http://dx.doi.org/10.3762/bjoc.8.130.

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A number of physicochemical characteristics have been described which contribute to the biological activity of antimicrobial peptides. This information was used to design a novel antimicrobial peptide sequence by using an intrinsically inactive membrane-associated peptide derived from the HIV glycoprotein, gp41, as a starting scaffold. This peptide corresponds to the tryptophan-rich membrane-proximal region of gp41, which is known to interact at the interfacial region of the viral membrane and adopts a helical structure in the presence of lipids. Three synthetic peptides were designed to increase the net positive charge and amphipathicity of this 19-residue peptide. Ultimately, the peptide with the greatest degree of amphipathicity and largest positive charge proved to be the most potent antimicrobial, and this peptide could be further modified to improve the antimicrobial activity. However, the other two peptides were relatively ineffective antimicrobials and instead proved to be extremely hemolytic. This work demonstrates a novel approach for the design of unexplored antimicrobial peptide sequences but it also reveals that the biological and cytotoxic activities of these polypeptides depend on a number of interrelated factors.
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Nava Lara, Rodrigo, Longendri Aguilera-Mendoza, Carlos Brizuela, Antonio Peña, and Gabriel Del Rio. "Heterologous Machine Learning for the Identification of Antimicrobial Activity in Human-Targeted Drugs." Molecules 24, no. 7 (March 31, 2019): 1258. http://dx.doi.org/10.3390/molecules24071258.

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The emergence of microbes resistant to common antibiotics represent a current treat to human health. It has been recently recognized that non-antibiotic labeled drugs may promote antibiotic-resistance mechanisms in the human microbiome by presenting a secondary antibiotic activity; hence, the development of computer-assisted procedures to identify antibiotic activity in human-targeted compounds may assist in preventing the emergence of resistant microbes. In this regard, it is worth noting that while most antibiotics used to treat human infectious diseases are non-peptidic compounds, most known antimicrobials nowadays are peptides, therefore all computer-based models aimed to predict antimicrobials either use small datasets of non-peptidic compounds rendering predictions with poor reliability or they predict antimicrobial peptides that are not currently used in humans. Here we report a machine-learning-based approach trained to identify gut antimicrobial compounds; a unique aspect of our model is the use of heterologous training sets, in which peptide and non-peptide antimicrobial compounds were used to increase the size of the training data set. Our results show that combining peptide and non-peptide antimicrobial compounds rendered the best classification of gut antimicrobial compounds. Furthermore, this classification model was tested on the latest human-approved drugs expecting to identify antibiotics with broad-spectrum activity and our results show that the model rendered predictions consistent with current knowledge about broad-spectrum antibiotics. Therefore, heterologous machine learning rendered an efficient computational approach to classify antimicrobial compounds.
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Zhang, Yong-lian, and Hsiao-Chang Chan. "S1h1-4 An epididymis-specific antimicrobial peptide has dual functions in sperm maturation(S1-h1 "Antimicrobial Peptides and Membrane Interactions",Symposia,Abstract,Meeting Program of EABS & BSJ 2006)." Seibutsu Butsuri 46, supplement2 (2006): S113. http://dx.doi.org/10.2142/biophys.46.s113_2.

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Sutyak Noll, Katia, Mark N. Prichard, Arkady Khaykin, Patrick J. Sinko, and Michael L. Chikindas. "The Natural Antimicrobial Peptide Subtilosin Acts Synergistically with Glycerol Monolaurate, Lauric Arginate, and ε-Poly-l-Lysine against Bacterial Vaginosis-Associated Pathogens but Not Human Lactobacilli." Antimicrobial Agents and Chemotherapy 56, no. 4 (January 17, 2012): 1756–61. http://dx.doi.org/10.1128/aac.05861-11.

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ABSTRACTSubtilosin is a cyclical antimicrobial peptide produced byBacillus amyloliquefaciensthat has antimicrobial activity against the bacterial vaginosis-associated human pathogenGardnerella vaginalis. The ability of subtilosin to inhibitG. vaginalisalone and in combination with the natural antimicrobial agents glycerol monolaurate (Lauricidin), lauric arginate, and ε-poly-l-lysine was tested using a checkerboard approach. Subtilosin was found to act synergistically with all of the chosen antimicrobials. These promising results indicate that lower concentrations of subtilosin in combination with other compounds could effectively be used to inhibit growth of the pathogen, thereby decreasing the risk of developed antimicrobial resistance. This is the first report on the effects of subtilosin combined with other natural antimicrobials againstG. vaginalis.
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С., Саха, Ратрей П., and Мишра А. "ВЗАИМОДЕЙСТВИЕ АНТИМИКРОБНОГО ПЕПТИДА ЛАЗИОГЛОССИНА III С МОДЕЛЬНЫМИ ЛИПИДНЫМИ БИСЛОЯМИ." Биофизика 67, no. 2 (2022): 250–63. http://dx.doi.org/10.31857/s0006302922020077.

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Лазиоглоссин-III - малый катионный пептид, обнаруженный в яде пчелы Lasioglossum laticeps. Сообщается, что он обладает сильной антимикробной активностью и слабым гемолитическим действием. В данной работе исследована природа взаимодействий лазиоглоссина-III с липидными бислоями в различной ориентации и его проникающая способность с помощью расчетов методом молекулярной динамики. Были проведены молекулярно-динамические расчеты лазиоглоссина-III на поверхности и внутри бислоев из чистых 1,2-димиристоил-sn-глицеро-3-фосфатидилхолина и 1-пальмитоил-2-олеил-sn-глицеро-3-фосфатидилхолина для определения взаимодействий «мембрана-пептид» и их эффектов. Обнаружено, что лазиоглоссин-III взаимодействовал с обоими типами бислоев с разными скоростями и демонстрировал дестабилизацию на границе раздела фаз «мембрана-вода» относительно стартового состояния пептида. Эти результаты позволяют говорить о наличии специфических взаимодействий между остатками лизина пептида и участками головок липидов, ответственных за общую стабильность пептида в липидных бислоях. Кроме того, результаты указывают на существенно больший угол наклона пептида и более высокую свободную энергию, а также на уменьшение толщины бислоя в случае бислоев 1,2-димиристоил-sn-глицеро-3-фосфатидилхолина в сравнении с 1-пальмитоил-2-олеил-sn-глицеро-3-фосфатидилхолином, вызываемые встраиванием пептида.
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Kraszewska, Joanna, Michael C. Beckett, Tharappel C. James, and Ursula Bond. "Comparative Analysis of the Antimicrobial Activities of Plant Defensin-Like and Ultrashort Peptides against Food-Spoiling Bacteria." Applied and Environmental Microbiology 82, no. 14 (May 6, 2016): 4288–98. http://dx.doi.org/10.1128/aem.00558-16.

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ABSTRACTAntimicrobial peptides offer potential as novel therapeutics to combat food spoilage and poisoning caused by pathogenic and nonpathogenic bacteria. Our previous studies identified the peptide human beta-defensin 3 (HBD3) as a potent antimicrobial agent against a wide range of beer-spoiling bacteria. Thus, HBD3 is an excellent candidate for development as an additive to prevent food and beverage spoilage. To expand the repertoire of peptides with antimicrobial activity against bacteria associated with food spoilage and/or food poisoning, we carried out anin silicodiscovery pipeline to identify peptides with structure and activity similar to those of HBD3, focusing on peptides of plant origin. Using a standardized assay, we compared the antimicrobial activities of nine defensin-like plant peptides to the activity of HBD3. Only two of the peptides, fabatin-2 and Cp-thionin-2, displayed antimicrobial activity; however, the peptides differed from HBD3 in being sensitive to salt and were thermostable. We also compared the activities of several ultrashort peptides to that of HBD3. One of the peptides, the synthetic tetrapeptide O3TR, displayed biphasic antimicrobial activity but had a narrower host range than HBD3. Finally, to determine if the peptides might act in concert to improve antimicrobial activity, we compared the activities of the peptides in pairwise combinations. The plant defensin-like peptides fabatin-2 and Cp-thionin-2 displayed a synergistic effect with HBD3, while O3TR was antagonistic. Thus, some plant defensin-like peptides are effective antimicrobials and may act in concert with HBD3 to control bacteria associated with food spoilage and food poisoning.IMPORTANCEFood spoilage and food poisoning caused by bacteria can have major health and economic implications for human society. With the rise in resistance to conventional antibiotics, there is a need to identify new antimicrobials to combat these outbreaks in our food supply. Here we screened plant peptide databases to identify peptides that share structural similarity with the human defensin peptide HBD3, which has known antimicrobial activity against food-spoiling bacteria. We show that two of the plant peptides display antimicrobial activity against bacteria associated with food spoilage. When combined with HBD3, the peptides are highly effective. We also analyzed the activity of an easily made ultrashort synthetic peptide, O3TR. We show that this small peptide also displays antimicrobial activity against food-spoiling bacteria but is not as effective as HBD3 or the plant peptides. The plant peptides identified are good candidates for development as natural additives to prevent food spoilage.
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Matsuzaki, Katsumi. "S1h1-1 Interaction of the Archetypical Antimicrobial Peptide Magainin with Membranes : From Classics to Cutting Edge(S1-h1 "Antimicrobial Peptides and Membrane Interactions",Symposia,Abstract,Meeting Program of EABS & BSJ 2006)." Seibutsu Butsuri 46, supplement2 (2006): S112. http://dx.doi.org/10.2142/biophys.46.s112_3.

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Fleeman, Renee M., Luis A. Macias, Jennifer S. Brodbelt, and Bryan W. Davies. "Defining principles that influence antimicrobial peptide activity against capsulatedKlebsiella pneumoniae." Proceedings of the National Academy of Sciences 117, no. 44 (October 21, 2020): 27620–26. http://dx.doi.org/10.1073/pnas.2007036117.

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The extracellular polysaccharide capsule ofKlebsiella pneumoniaeresists penetration by antimicrobials and protects the bacteria from the innate immune system. Host antimicrobial peptides are inactivated by the capsule as it impedes their penetration to the bacterial membrane. While the capsule sequesters most peptides, a few antimicrobial peptides have been identified that retain activity against encapsulatedK. pneumoniae,suggesting that this bacterial defense can be overcome. However, it is unclear what factors allow peptides to avoid capsule inhibition. To address this, we created a peptide analog with strong antimicrobial activity toward severalK. pneumoniaestrains from a previously inactive peptide. We characterized the effects of these two peptides onK. pneumoniae, along with their physical interactions withK. pneumoniaecapsule. Both peptides disrupted bacterial cell membranes, but only the active peptide displayed this activity against capsulatedK. pneumoniae. Unexpectedly, the active peptide showed no decrease in capsule binding, but did lose secondary structure in a capsule-dependent fashion compared with the inactive parent peptide. We found that these characteristics are associated with capsule-peptide aggregation, leading to disruption of theK. pneumoniaecapsule. Our findings reveal a potential mechanism for disrupting the protective barrier thatK. pneumoniaeuses to avoid the immune system and last-resort antibiotics.
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Gauri, Samiran Sona, Chandan Kumar Bera, Rabindranath Bhattacharyya, and Santi Mohan Mandal. "Identification of an antimicrobial peptide from large freshwater snail (Lymnaea stagnalis): activity against antibiotics resistant Staphylococcus epidermidis." INTERNATIONAL JOURNAL OF EXPERIMENTAL RESEARCH AND REVIEW 2 (January 30, 2016): 5–9. http://dx.doi.org/10.52756/ijerr.2016.v2.002.

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Nowadays, antibiotic resistance in bacteria is a great public health problem of increasing magnitude due to quick evolution through mutation that has generated the urgency to find the effective solutions to address this problem. Aside the conventional antibiotics, antimicrobial peptides are a new class of antimicrobials is known to have the activity against a wide range of bacteria. An antimicrobial peptide was isolated and purified from the Lymnaea stagnalis, a fresh water large snail, using ultrafiltration and reversed phase liquid chromatography. The molecular mass of the peptide 2345 Da was determined using MALDI TOF mass spectrometry. This peptide is efficiently prevented the growth of Staphylococcus epidermidis that resistant to ampicillin and chloramphenicol antibiotics. The MIC value was 16 μg/mL and specifically damage to bacterial membranes. Hence, this reported peptide revealed an alternative candidate to controlling the Staphylococcal infections.
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He, Zengguo, Duygu Kisla, Liwen Zhang, Chunhua Yuan, Kari B. Green-Church, and Ahmed E. Yousef. "Isolation and Identification of a Paenibacillus polymyxa Strain That Coproduces a Novel Lantibiotic and Polymyxin." Applied and Environmental Microbiology 73, no. 1 (October 27, 2006): 168–78. http://dx.doi.org/10.1128/aem.02023-06.

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ABSTRACT A new bacterial strain, displaying potent antimicrobial properties against gram-negative and gram-positive pathogenic bacteria, was isolated from food. Based on its phenotypical and biochemical properties as well as its 16S rRNA gene sequence, the bacterium was identified as Paenibacillus polymyxa and it was designated as strain OSY-DF. The antimicrobials produced by this strain were isolated from the fermentation broth and subsequently analyzed by liquid chromatography-mass spectrometry. Two antimicrobials were found: a known antibiotic, polymyxin E1, which is active against gram-negative bacteria, and an unknown 2,983-Da compound showing activity against gram-positive bacteria. The latter was purified to homogeneity, and its antimicrobial potency and proteinaceous nature were confirmed. The antimicrobial peptide, designated paenibacillin, is active against a broad range of food-borne pathogenic and spoilage bacteria, including Bacillus spp., Clostridium sporogenes, Lactobacillus spp., Lactococcus lactis, Leuconostoc mesenteroides, Listeria spp., Pediococcus cerevisiae, Staphylococcus aureus, and Streptococcus agalactiae. Furthermore, it possesses the physico-chemical properties of an ideal antimicrobial agent in terms of water solubility, thermal resistance, and stability against acid/alkali (pH 2.0 to 9.0) treatment. Edman degradation, mass spectroscopy, and nuclear magnetic resonance were used to sequence native and chemically modified paenibacillin. While details of the tentative sequence need to be elucidated in future work, the peptide was unequivocally characterized as a novel lantibiotic, with a high degree of posttranslational modifications. The coproduction of polymyxin E1 and a lantibiotic is a finding that has not been reported earlier. The new strain and associated peptide are potentially useful in food and medical applications.
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Ménard, Sandrine, Valentina Förster, Michael Lotz, Dominique Gütle, Claudia U. Duerr, Richard L. Gallo, Birgitta Henriques-Normark, et al. "Developmental switch of intestinal antimicrobial peptide expression." Journal of Experimental Medicine 205, no. 1 (January 7, 2008): 183–93. http://dx.doi.org/10.1084/jem.20071022.

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Paneth cell–derived enteric antimicrobial peptides provide protection from intestinal infection and maintenance of enteric homeostasis. Paneth cells, however, evolve only after the neonatal period, and the antimicrobial mechanisms that protect the newborn intestine are ill defined. Using quantitative reverse transcription–polymerase chain reaction, immunohistology, reverse-phase high-performance liquid chromatography, and mass spectrometry, we analyzed the antimicrobial repertoire in intestinal epithelial cells during postnatal development. Surprisingly, constitutive expression of the cathelin-related antimicrobial peptide (CRAMP) was observed, and the processed, antimicrobially active form was identified in neonatal epithelium. Peptide synthesis was limited to the first two weeks after birth and gradually disappeared with the onset of increased stem cell proliferation and epithelial cell migration along the crypt–villus axis. CRAMP conferred significant protection from intestinal bacterial growth of the newborn enteric pathogen Listeria monocytogenes. Thus, we describe the first example of a complete developmental switch in innate immune effector expression and anatomical distribution. Epithelial CRAMP expression might contribute to bacterial colonization and the establishment of gut homeostasis, and provide protection from enteric infection during the postnatal period.
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Green, R. Madison, and Kevin L. Bicker. "Evaluation of peptoid mimics of short, lipophilic peptide antimicrobials." International Journal of Antimicrobial Agents 56, no. 2 (August 2020): 106048. http://dx.doi.org/10.1016/j.ijantimicag.2020.106048.

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Das, Bharati, and Maneesh Jain. "A New and Promising Avenue In Selective Antimicrobial Treatment For Particularly Targeted Antimicrobial Peptides." Journal of Advances and Scholarly Researches in Allied Education 15, no. 7 (September 1, 2018): 69–75. http://dx.doi.org/10.29070/15/57667.

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Epand, Raquel F., Guangshun Wang, Bob Berno, and Richard M. Epand. "Lipid Segregation Explains Selective Toxicity of a Series of Fragments Derived from the Human Cathelicidin LL-37." Antimicrobial Agents and Chemotherapy 53, no. 9 (July 6, 2009): 3705–14. http://dx.doi.org/10.1128/aac.00321-09.

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ABSTRACT The only human cathelicidin, the 37-residue peptide LL-37, exhibits antimicrobial activity against both gram-positive and gram-negative bacteria. We studied the ability of several fragments of LL-37, exhibiting different antimicrobial activities, to interact with membranes whose compositions mimic the cytoplasmic membranes of gram-positive or of gram-negative bacteria. These fragments are as follows: KR-12, the smallest active segment of LL-37, with the sequence KRIVQRIKDFLR, which exhibits antimicrobial activity only against gram-negative bacteria; a slightly smaller peptide, RI-10, missing the two cationic residues at the N and C termini of KR-12, which has been shown not to have any antimicrobial activity; a longer peptide, GF-17, which shows antimicrobial activity against gram-positive as well as gram-negative bacteria; and GF-17D3, with 3 d-amino-acid residues, which is also selective only for gram-negative bacteria. Those fragments with the capacity to cluster anionic lipids away from zwitterionic lipids in a membrane exhibit selective toxicity toward bacteria containing zwitterionic as well as anionic lipids in their cytoplasmic membranes but not toward bacteria with only anionic lipids. This finding allows for the prediction of the bacterial-species selectivity of certain agents and paves the way for designing new antimicrobials targeted specifically toward gram-negative bacteria.
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Silva, Osmar N., Marcelo D. T. Torres, Jicong Cao, Elaine S. F. Alves, Leticia V. Rodrigues, Jarbas M. Resende, Luciano M. Lião, et al. "Repurposing a peptide toxin from wasp venom into antiinfectives with dual antimicrobial and immunomodulatory properties." Proceedings of the National Academy of Sciences 117, no. 43 (October 12, 2020): 26936–45. http://dx.doi.org/10.1073/pnas.2012379117.

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Novel antibiotics are urgently needed to combat multidrug-resistant pathogens. Venoms represent previously untapped sources of novel drugs. Here we repurposed mastoparan-L, the toxic active principle derived from the venom of the wasp Vespula lewisii, into synthetic antimicrobials. We engineered within its N terminus a motif conserved among natural peptides with potent immunomodulatory and antimicrobial activities. The resulting peptide, mast-MO, adopted an α-helical structure as determined by NMR, exhibited increased antibacterial properties comparable to standard-of-care antibiotics both in vitro and in vivo, and potentiated the activity of different classes of antibiotics. Mechanism-of-action studies revealed that mast-MO targets bacteria by rapidly permeabilizing their outer membrane. In animal models, the peptide displayed direct antimicrobial activity, led to enhanced ability to attract leukocytes to the infection site, and was able to control inflammation. Permutation studies depleted the remaining toxicity of mast-MO toward human cells, yielding derivatives with antiinfective activity in animals. We demonstrate a rational design strategy for repurposing venoms into promising antimicrobials.
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Boparai, Jaspreet Kaur, and Pushpender Kumar Sharma. "Mini Review on Antimicrobial Peptides, Sources, Mechanism and Recent Applications." Protein & Peptide Letters 27, no. 1 (December 10, 2019): 4–16. http://dx.doi.org/10.2174/0929866526666190822165812.

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Antimicrobial peptides in recent years have gained increased interest among scientists, health professionals and the pharmaceutical companies owing to their therapeutic potential. These are low molecular weight proteins with broad range antimicrobial and immuno modulatory activities against infectious bacteria (Gram positive and Gram negative), viruses and fungi. Inability of micro-organisms to develop resistance against most of the antimicrobial peptide has made them as an efficient product which can greatly impact the new era of antimicrobials. In addition to this these peptides also demonstrates increased efficacy, high specificity, decreased drug interaction, low toxicity, biological diversity and direct attacking properties. Pharmaceutical industries are therefore conducting appropriate clinical trials to develop these peptides as potential therapeutic drugs. More than 60 peptide drugs have already reached the market and several hundreds of novel therapeutic peptides are in preclinical and clinical development. Rational designing can be used further to modify the chemical and physical properties of existing peptides. This mini review will discuss the sources, mechanism and recent therapeutic applications of antimicrobial peptides in treatment of infectious diseases.
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Eckert, Randal, Fengxia Qi, Daniel K. Yarbrough, Jian He, Maxwell H. Anderson, and Wenyuan Shi. "Adding Selectivity to Antimicrobial Peptides: Rational Design of a Multidomain Peptide against Pseudomonas spp." Antimicrobial Agents and Chemotherapy 50, no. 4 (April 2006): 1480–88. http://dx.doi.org/10.1128/aac.50.4.1480-1488.2006.

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ABSTRACT Currently available antimicrobials exhibit broad killing with regard to bacterial genera and species. Indiscriminate killing of microbes by these conventional antibiotics can disrupt the ecological balance of the indigenous microbial flora, often resulting in negative clinical consequences. Species-specific antimicrobials capable of precisely targeting pathogenic bacteria without damaging benign microorganisms provide a means of avoiding this problem. In this communication, we report the successful creation of the first synthetic, target-specific antimicrobial peptide, G10KHc, via addition of a rationally designed Pseudomonas-specific targeting moiety (KH) to a generally killing peptide (novispirin G10). The resulting chimeric peptide showed enhanced bactericidal activity and faster killing kinetics against Pseudomonas spp. than G10 alone. The enhanced killing activities are due to increased binding and penetration of the outer membrane of Pseudomonas sp. cells. These properties were not observed in tests of untargeted bacterial species, and this specificity allowed G10KHc to selectively eliminate Pseudomonas spp. from mixed cultures. This work lays a foundation for generating target-specific “smart” antimicrobials to complement currently available conventional antibiotics.
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Kopeykin, P. M., M. S. Sukhareva, N. V. Lugovkina, and O. V. Shamova. "CHEMICAL SYNTHESIS AND ANALYSIS OF ANTIMICROBIAL AND HEMOLYTIC ACTIVITY OF STRUCTURAL ANALOGOUS OF A PEPTIDE PROTEGRIN 1." Medical academic journal 19, no. 1S (December 15, 2019): 169–70. http://dx.doi.org/10.17816/maj191s1169-170.

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Search for new tools for combating infectious diseases and investigation of molecular mechanisms of their antimicrobial action in in vitro and in vivo models are the urgent tasks of experimental medicine and pathophysiology. A promising direction for the development of new effective antibiotic drugs is creation of analogues of natural protective molecules that provide a host defense against pathogenic bacteria, in particular analogues of antimicrobial peptides of the innate immune system. The aim of our work was design, chemical synthesis and characterization of antimicrobial and hemolytic activity of a peptide protegrin 1 (PG1) structural variants. Three analogues of PG1 were produced and studied, it was shown that two PG1 variants exhibit a high activity against antibiotic-resistant bacteria. A comparative analysis of the hemolytic activity of the peptides towards human erythrocytes was carried out. The ways of further work directed to creation of novel antimicrobials based on a natural peptide PG1 for combating drug-resistant bacteria are outlined.
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Alkatheri, Asma Hussain, Polly Soo-Xi Yap, Aisha Abushelaibi, Kok-Song Lai, Wan-Hee Cheng, and Swee-Hua Erin Lim. "Host–Bacterial Interactions: Outcomes of Antimicrobial Peptide Applications." Membranes 12, no. 7 (July 19, 2022): 715. http://dx.doi.org/10.3390/membranes12070715.

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The bacterial membrane is part of a secretion system which plays an integral role to secrete proteins responsible for cell viability and pathogenicity; pathogenic bacteria, for example, secrete virulence factors and other membrane-associated proteins to invade the host cells through various types of secretion systems (Type I to Type IX). The bacterial membrane can also mediate microbial communities’ communication through quorum sensing (QS), by secreting auto-stimulants to coordinate gene expression. QS plays an important role in regulating various physiological processes, including bacterial biofilm formation while providing increased virulence, subsequently leading to antimicrobial resistance. Multi-drug resistant (MDR) bacteria have emerged as a threat to global health, and various strategies targeting QS and biofilm formation have been explored by researchers worldwide. Since the bacterial secretion systems play such a crucial role in host–bacterial interactions, this review intends to outline current understanding of bacterial membrane systems, which may provide new insights for designing approaches aimed at antimicrobials discovery. Various mechanisms pertaining interaction of the bacterial membrane with host cells and antimicrobial agents will be highlighted, as well as the evolution of bacterial membranes in evasion of antimicrobial agents. Finally, the use of antimicrobial peptides (AMPs) as a cellular device for bacterial secretion systems will be discussed as emerging potential candidates for the treatment of multidrug resistance infections.
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Hu, Alvin. "Conjugation of Silver Nanoparticles With De Novo–Engineered Cationic Antimicrobial Peptides: Exploratory Proposal." JMIR Research Protocols 10, no. 12 (December 8, 2021): e28307. http://dx.doi.org/10.2196/28307.

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Background Cationic antimicrobial peptides have broad antimicrobial activity and provide a novel way of targeting multidrug-resistant bacteria in the era of increasing antimicrobial resistance. Current developments show positive prospects for antimicrobial peptides and silver nanoparticles (AgNPs) individually. Objective The primary objective is to propose another method for enhancing antimicrobial activity by conjugating AgNPs with cationic antimicrobial peptides, with a subsequent preliminary assessment of the minimum inhibitory concentration of multidrug-resistant bacteria. The secondary objective is to evaluate the safety of the conjugated compound and assess its viability for in vivo use. Methods The proposal involves 3 stages. First, WLBU2C, a modified version of the antimicrobial peptide WLBU2 with an added cysteine group, needs to be synthesized using a standard Fmoc procedure. It can then be stably conjugated with AgNPs ideally through photochemical means. Second, the WLBU2C-AgNP conjugate should be tested for antimicrobial activity according to the Clinical & Laboratory Standards Institute manual on standard minimum inhibitory concentration testing. Third, the cytotoxicity of the conjugate should be tested using cell lysis assays if the above stages are completed. Results I-TASSER (iterative threading assembly refinement) simulation revealed that the modified peptide WLBU2C has a secondary structure similar to that of the original WLBU2 peptide. No other results have been obtained at this time. Conclusions The addition of AgNPs to already developed de novo–engineered antimicrobial peptides provides an opportunity for the development of potent antimicrobials. Future prospects include emergency last-line therapy and treatment for current difficult-to-eradicate bacterial colonization, such as in cystic fibrosis, implantable medical devices, cancer, and immunotherapy. As I do not anticipate funding at this time, I hope this proposal provides inspiration to other researchers. International Registered Report Identifier (IRRID) PRR1-10.2196/28307
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Cesaro, Angela, Rosa Gaglione, Marco Chino, Maria De Luca, Rocco Di Girolamo, Angelina Lombardi, Rosanna Filosa, and Angela Arciello. "Novel Retro-Inverso Peptide Antibiotic Efficiently Released by a Responsive Hydrogel-Based System." Biomedicines 10, no. 6 (June 2, 2022): 1301. http://dx.doi.org/10.3390/biomedicines10061301.

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Topical antimicrobial treatments are often ineffective on recalcitrant and resistant skin infections. This necessitates the design of antimicrobials that are less susceptible to resistance mechanisms, as well as the development of appropriate delivery systems. These two issues represent a great challenge for researchers in pharmaceutical and drug discovery fields. Here, we defined the therapeutic properties of a novel peptidomimetic inspired by an antimicrobial sequence encrypted in human apolipoprotein B. The peptidomimetic was found to exhibit antimicrobial and anti-biofilm properties at concentration values ranging from 2.5 to 20 µmol L−1, to be biocompatible toward human skin cell lines, and to protect human keratinocytes from bacterial infections being able to induce a reduction of bacterial units by two or even four orders of magnitude with respect to untreated samples. Based on these promising results, a hyaluronic-acid-based hydrogel was devised to encapsulate and to specifically deliver the selected antimicrobial agent to the site of infection. The developed hydrogel-based system represents a promising, effective therapeutic option by combining the mechanical properties of the hyaluronic acid polymer with the anti-infective activity of the antimicrobial peptidomimetic, thus opening novel perspectives in the treatment of skin infections.
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Ciura, Krzesimir, Natalia Ptaszyńska, Hanna Kapica, Monika Pastewska, Anna Łęgowska, Krzysztof Rolka, Wojciech Kamysz, Wiesław Sawicki, and Katarzyna E. Greber. "Can Immobilized Artificial Membrane Chromatography Support the Characterization of Antimicrobial Peptide Origin Derivatives?" Antibiotics 10, no. 10 (October 12, 2021): 1237. http://dx.doi.org/10.3390/antibiotics10101237.

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The emergence and spread of multiple drug-resistant bacteria strains caused the development of new antibiotics to be one of the most important challenges of medicinal chemistry. Despite many efforts, the commercial availability of peptide-based antimicrobials is still limited. The presented study aims to explain that immobilized artificial membrane chromatography can support the characterization of antimicrobial peptides. Consequently, the chromatographic experiments of three groups of related peptide substances: (i) short cationic lipopeptides, (ii) citropin analogs, and (iii) conjugates of ciprofloxacin and levofloxacin, with a cell-penetrating peptide were discussed. In light of the discussion of the mechanisms of action of these compounds, the obtained results were interpreted.
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Raj, Periathamby Antony, Latha Rajkumar, and Andrew R. Dentino. "Novel molecules for intra-oral delivery of antimicrobials to prevent and treat oral infectious diseases." Biochemical Journal 409, no. 2 (December 21, 2007): 601–9. http://dx.doi.org/10.1042/bj20070810.

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New molecules were designed for efficient intra-oral delivery of antimicrobials to prevent and treat oral infection. The salivary statherin fragment, which has high affinity for the tooth enamel, was used as a carrier peptide. This was linked through the side chain of the N-terminal residue to the C-terminus of a defensin-like 12-residue peptide to generate two bifunctional hybrid molecules, one with an ester linkage and the other with an anhydride bond between the carrier and the antimicrobial components. They were examined for their affinity to a HAP (hydroxyapatite) surface. The extent of the antimicrobial release in human whole saliva was determined using 13C-NMR spectroscopy. The candidacidal activity of the molecules was determined as a function of the antimicrobial release from the carrier peptide in human saliva. The hybrid-adsorbed HAP surface was examined against Candida albicans and Aggregatibacter actinomycetemcomitans using the fluorescence technique. The bifunctional molecules were tested on human erythrocytes, GECs (gingival epithelial cells) and GFCs (gingival fibroblast cells) for cytotoxicity. They were found to possess high affinity for the HAP mineral. In human whole saliva, a sustained antimicrobial release over a period of more than 40–60 h, and candidacidal activity consistent with the extent of hybrid dissociation were observed. Moreover, the bifunctional peptide-bound HAP surface was found to exhibit antimicrobial activity when suspended in clarified human saliva. The hybrid peptides did not show any toxic influence on human erythrocytes, GECs and GFCs. These novel hybrids could be safely used to deliver therapeutic agents intra-orally for the treatment and prevention of oral infectious diseases.
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Salillas, Sandra, Juan José Galano-Frutos, Alejandro Mahía, Ritwik Maity, María Conde-Giménez, Ernesto Anoz-Carbonell, Helena Berlamont, et al. "Selective Targeting of Human and Animal Pathogens of the Helicobacter Genus by Flavodoxin Inhibitors: Efficacy, Synergy, Resistance and Mechanistic Studies." International Journal of Molecular Sciences 22, no. 18 (September 20, 2021): 10137. http://dx.doi.org/10.3390/ijms221810137.

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Antimicrobial resistant (AMR) bacteria constitute a global health concern. Helicobacter pylori is a Gram-negative bacterium that infects about half of the human population and is a major cause of peptic ulcer disease and gastric cancer. Increasing resistance to triple and quadruple H. pylori eradication therapies poses great challenges and urges the development of novel, ideally narrow spectrum, antimicrobials targeting H. pylori. Here, we describe the antimicrobial spectrum of a family of nitrobenzoxadiazol-based antimicrobials initially discovered as inhibitors of flavodoxin: an essential H. pylori protein. Two groups of inhibitors are described. One group is formed by narrow-spectrum compounds, highly specific for H. pylori, but ineffective against enterohepatic Helicobacter species and other Gram-negative or Gram-positive bacteria. The second group includes extended-spectrum antimicrobials additionally targeting Gram-positive bacteria, the Gram-negative Campylobacter jejuni, and most Helicobacter species, but not affecting other Gram-negative pathogens. To identify the binding site of the inhibitors in the flavodoxin structure, several H. pylori-flavodoxin variants have been engineered and tested using isothermal titration calorimetry. An initial study of the inhibitors capacity to generate resistances and of their synergism with antimicrobials commonly used in H. pylori eradication therapies is described. The narrow-spectrum inhibitors, which are expected to affect the microbiota less dramatically than current antimicrobial drugs, offer an opportunity to develop new and specific H. pylori eradication combinations to deal with AMR in H. pylori. On the other hand, the extended-spectrum inhibitors constitute a new family of promising antimicrobials, with a potential use against AMR Gram-positive bacterial pathogens.
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Nan, Yong, Ka Park, Young Jeon, Yoonkyung Park, Il-Seon Park, Kyung-Soo Hahm, and Song Shin. "Antimicrobial and Anti-Inflammatory Activities of a Leu/Lys-Rich Antimicrobial Peptide with Phe-Peptoid Residues." Protein & Peptide Letters 14, no. 10 (October 1, 2007): 1003–7. http://dx.doi.org/10.2174/092986607782541042.

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31

Fernández, Lucía, W. James Gooderham, Manjeet Bains, Joseph B. McPhee, Irith Wiegand, and Robert E. W. Hancock. "Adaptive Resistance to the “Last Hope” Antibiotics Polymyxin B and Colistin in Pseudomonas aeruginosa Is Mediated by the Novel Two-Component Regulatory System ParR-ParS." Antimicrobial Agents and Chemotherapy 54, no. 8 (June 14, 2010): 3372–82. http://dx.doi.org/10.1128/aac.00242-10.

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ABSTRACT As multidrug resistance increases alarmingly, polymyxin B and colistin are increasingly being used in the clinic to treat serious Pseudomonas aeruginosa infections. In this opportunistic pathogen, subinhibitory levels of polymyxins and certain antimicrobial peptides induce resistance toward higher, otherwise lethal, levels of these antimicrobial agents. It is known that the modification of lipid A of lipopolysaccharide (LPS) is a key component of this adaptive peptide resistance, but to date, the regulatory mechanism underlying peptide regulation in P. aeruginosa has remained elusive. The PhoP-PhoQ and PmrA-PmrB two-component systems, which control this modification under low-Mg2+ conditions, do not appear to play a major role in peptide-mediated adaptive resistance, unlike in Salmonella where PhoQ is a peptide sensor. Here we describe the identification and characterization of a novel P. aeruginosa two-component regulator affecting p olymyxin- a daptive r esistance, ParR-ParS (PA1799-PA1798). This system was required for activation of the arnBCADTEF LPS modification operon in the presence of subinhibitory concentrations of polymyxin, colistin, or the bovine peptide indolicidin, leading to increased resistance to various polycationic antibiotics, including aminoglycosides. This study highlights the complexity of the regulatory network controlling resistance to cationic antibiotics and host peptides in P. aeruginosa, which has major relevance in the development and deployment of cationic antimicrobials.
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Sarangi, Tamalika, S. Ramakrishnan, and S. Nakkeeran. "Antimicrobial Peptide Genes Present in Indigenous Isolates of Bacillus spp. Exhibiting Antimicrobical Properties." International Journal of Current Microbiology and Applied Sciences 6, no. 8 (August 10, 2017): 1361–69. http://dx.doi.org/10.20546/ijcmas.2017.608.166.

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33

Patrzykat, Aleksander, Jeffrey W. Gallant, Jung-Kil Seo, Jennifer Pytyck, and Susan E. Douglas. "Novel Antimicrobial Peptides Derived from Flatfish Genes." Antimicrobial Agents and Chemotherapy 47, no. 8 (August 2003): 2464–70. http://dx.doi.org/10.1128/aac.47.8.2464-2470.2003.

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ABSTRACT We report on the identification of active novel antimicrobials determined by screening both the genomic information and the mRNA transcripts from a number of different flatfish for sequences encoding antimicrobial peptides, predicting the sequences of active peptides from the genetic information, producing the predicted peptides chemically, and testing them for their activities. We amplified 35 sequences from various species of flatfish using primers whose sequences are based on conserved flanking regions of a known antimicrobial peptide from winter flounder, pleurocidin. We analyzed the sequences of the amplified products and predicted which sequences were likely to encode functional antimicrobial peptides on the basis of charge, hydrophobicity, relation to flanking sequences, and similarity to known active peptides. Twenty peptides were then produced synthetically and tested for their activities against gram-positive and gram-negative bacteria and the yeast Candida albicans. The most active peptide (with the carboxy-terminus amidated sequence GWRTLLKKAEVKTVGKLALKHYL, derived from American plaice) showed inhibitory activity over a concentration range of 1 to 8 μg/ml against a test panel of pathogens, including the intrinsically antibiotic-resistant organism Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and C. albicans. The methods described here will be useful for the identification of novel peptides with good antimicrobial activities.
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Jenssen, Håvard, Pamela Hamill, and Robert E. W. Hancock. "Peptide Antimicrobial Agents." Clinical Microbiology Reviews 19, no. 3 (July 2006): 491–511. http://dx.doi.org/10.1128/cmr.00056-05.

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SUMMARY Antimicrobial host defense peptides are produced by all complex organisms as well as some microbes and have diverse and complex antimicrobial activities. Collectively these peptides demonstrate a broad range of antiviral and antibacterial activities and modes of action, and it is important to distinguish between direct microbicidal and indirect activities against such pathogens. The structural requirements of peptides for antiviral and antibacterial activities are evaluated in light of the diverse set of primary and secondary structures described for host defense peptides. Peptides with antifungal and antiparasitic activities are discussed in less detail, although the broad-spectrum activities of such peptides indicate that they are important host defense molecules. Knowledge regarding the relationship between peptide structure and function as well as their mechanism of action is being applied in the design of antimicrobial peptide variants as potential novel therapeutic agents.
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El-Sayed Amr, Abd El-Galil, Mohamed Abo-Ghalia, and Mohamed M. Abdalah. "Synthesis of Novel Macrocyclic Peptido-calix[4]arenes and Peptidopyridines as Precursors for Potential Molecular Metallacages, Chemosensors and Biologically Active Candidates." Zeitschrift für Naturforschung B 61, no. 11 (November 1, 2006): 1335–45. http://dx.doi.org/10.1515/znb-2006-1104.

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Novel macrocyclic dipicolinic acid acylated peptides based on upper rim bridged peptidocalix[ 4]arenes, peptido-pyridines or hybrid structures of both, were synthesized as potential molecular metallacages and chemosensors. While conventional azide or mixed anhydride (ethyl chloroformate) peptide couplings served well for assembling the L-tyrosine or L-ornithine peptide backbones, the acid chloride of pyridine-2,6-dicarboxylic acid (dipicolinic acid) acid served as the complementary acylating agent. The structure assignment of the new compounds was based on chemical and spectroscopic evidences. Some of these compounds exhibit antimicrobial activities.
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Righetto, Gabriela Marinho, José Luiz de Souza Lopes, Paulo José Martins Bispo, Camille André, Julia Medeiros Souza, Adriano Defini Andricopulo, Leila Maria Beltramini, and Ilana Lopes Baratella da Cunha Camargo. "Antimicrobial Activity of an Fmoc-Plantaricin 149 Derivative Peptide against Multidrug-Resistant Bacteria." Antibiotics 12, no. 2 (February 15, 2023): 391. http://dx.doi.org/10.3390/antibiotics12020391.

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Antimicrobial resistance poses a major threat to public health. Given the paucity of novel antimicrobials to treat resistant infections, the emergence of multidrug-resistant bacteria renewed interest in antimicrobial peptides as potential therapeutics. This study designed a new analog of the antimicrobial peptide Plantaricin 149 (Pln149-PEP20) based on previous Fmoc-peptides. The minimal inhibitory concentrations of Pln149-PEP20 were determined for 60 bacteria of different species and resistance profiles, ranging from 1 mg/L to 128 mg/L for Gram-positive bacteria and 16 to 512 mg/L for Gram-negative. Furthermore, Pln149-PEP20 demonstrated excellent bactericidal activity within one hour. To determine the propensity to develop resistance to Pln149-PEP20, a directed-evolution in vitro experiment was performed. Whole-genome sequencing of selected mutants with increased MICs and wild-type isolates revealed that most mutations were concentrated in genes associated with membrane metabolism, indicating the most likely target of Pln149-PEP20. Synchrotron radiation circular dichroism showed how this molecule disturbs the membranes, suggesting a carpet mode of interaction. Membrane depolarization and transmission electron microscopy assays supported these two hypotheses, although a secondary intracellular mechanism of action is possible. The molecule studied in this research has the potential to be used as a novel antimicrobial therapy, although further modifications and optimization remain possible.
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Greco, Ines, Johannes Hansen, Bimal Jana, Natalia Molchanova, Alberto Oddo, Peter Thulstrup, Peter Damborg, Luca Guardabassi, and Paul Hansen. "Structure–Activity Study, Characterization, and Mechanism of Action of an Antimicrobial Peptoid D2 and Its d- and l-Peptide Analogues." Molecules 24, no. 6 (March 21, 2019): 1121. http://dx.doi.org/10.3390/molecules24061121.

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Methicillin-resistant Staphylococcus pseudintermedius (MRSP) constitutes an emerging health problem for companion animals in veterinary medicine. Therefore, discovery of novel antimicrobial agents for treatment of Staphylococcus-associated canine infections is urgently needed to reduce use of human antibiotics in veterinary medicine. In the present work, we characterized the antimicrobial activity of the peptoid D2 against S. pseudintermedius and Pseudomonas aeruginosa, which is another common integumentary pathogen in dogs. Furthermore, we performed a structure–activity relationship study of D2, which included 19 peptide/peptoid analogs. Our best compound D2D, an all d-peptide analogue, showed potent minimum inhibitory concentrations (MICs) against canine S. pseudintermedius (2–4 µg/mL) and P. aeruginosa (4 µg/mL) isolates as well as other selected dog pathogens (2–16 µg/mL). Time–kill assays demonstrated that D2D was able to inhibit MRSP in 30 min at 1× MIC, significantly faster than D2. Our results suggest that at high concentrations D2D is rapidly lysing the bacterial membrane while D2 is inhibiting macromolecular synthesis. We probed the mechanism of action at sub-MIC concentrations of D2, D2D, the l-peptide analog and its retro analog by a macromolecular biosynthesis assay and fluorescence spectroscopy. Our data suggest that at sub-MIC concentrations D2D is membrane inactive and primarily works by cell wall inhibition, while the other compounds mainly act on the bacterial membrane.
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Ruijne, Fleur, and Oscar P. Kuipers. "Combinatorial biosynthesis for the generation of new-to-nature peptide antimicrobials." Biochemical Society Transactions 49, no. 1 (January 13, 2021): 203–15. http://dx.doi.org/10.1042/bst20200425.

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Natural peptide products are a valuable source of important therapeutic agents, including antibiotics, antivirals and crop protection agents. Aided by an increased understanding of structure–activity relationships of these complex molecules and the biosynthetic machineries that produce them, it has become possible to re-engineer complete machineries and biosynthetic pathways to create novel products with improved pharmacological properties or modified structures to combat antimicrobial resistance. In this review, we will address the progress that has been made using non-ribosomally produced peptides and ribosomally synthesized and post-translationally modified peptides as scaffolds for designed biosynthetic pathways or combinatorial synthesis for the creation of novel peptide antimicrobials.
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Nava Lara, Rodrigo A., Jesús A. Beltrán, Carlos A. Brizuela, and Gabriel Del Rio. "Relevant Features of Polypharmacologic Human-Target Antimicrobials Discovered by Machine-Learning Techniques." Pharmaceuticals 13, no. 9 (August 21, 2020): 204. http://dx.doi.org/10.3390/ph13090204.

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Polypharmacologic human-targeted antimicrobials (polyHAM) are potentially useful in the treatment of complex human diseases where the microbiome is important (e.g., diabetes, hypertension). We previously reported a machine-learning approach to identify polyHAM from FDA-approved human targeted drugs using a heterologous approach (training with peptides and non-peptide compounds). Here we discover that polyHAM are more likely to be found among antimicrobials displaying a broad-spectrum antibiotic activity and that topological, but not chemical features, are most informative to classify this activity. A heterologous machine-learning approach was trained with broad-spectrum antimicrobials and tested with human metabolites; these metabolites were labeled as antimicrobials or non-antimicrobials based on a naïve text-mining approach. Human metabolites are not commonly recognized as antimicrobials yet circulate in the human body where microbes are found and our heterologous model was able to classify those with antimicrobial activity. These results provide the basis to develop applications aimed to design human diets that purposely alter metabolic compounds proportions as a way to control human microbiome.
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Janiszewska, Jolanta. "Natural antimicrobial peptides in biomedical applications." Polimery 59, no. 10 (October 2014): 699–707. http://dx.doi.org/10.14314/polimery.2014.699.

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41

Toole, Jamie, Hannah L. Bolt, John J. Marley, Sheila Patrick, Steven L. Cobb, and Fionnuala T. Lundy. "Peptoids with Antibiofilm Activity against the Gram Negative Obligate Anaerobe, Fusobacterium nucleatum." Molecules 26, no. 16 (August 5, 2021): 4741. http://dx.doi.org/10.3390/molecules26164741.

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Peptoids (oligo N-substituted glycines) are peptide analogues, which can be designed to mimic host antimicrobial peptides, with the advantage that they are resistant to proteolytic degradation. Few studies on the antimicrobial efficacy of peptoids have focused on Gram negative anaerobic microbes associated with clinical infections, which are commonly recalcitrant to antibiotic treatment. We therefore studied the cytotoxicity and antibiofilm activity of a family of peptoids against the Gram negative obligate anaerobe Fusobacterium nucleatum, which is associated with infections in the oral cavity. Two peptoids, peptoid 4 (NaeNpheNphe)4 and peptoid 9 (NahNspeNspe)3 were shown to be efficacious against F. nucleatum biofilms at a concentration of 1 μM. At this concentration, peptoids 4 and 9 were not cytotoxic to human erythrocytes or primary human gingival fibroblast cells. Peptoids 4 and 9 therefore have merit as future therapeutics for the treatment of oral infections.
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Nüsslein, Klaus, Lachelle Arnt, Jason Rennie, Cullen Owens, and Gregory N. Tew. "Broad-spectrum antibacterial activity by a novel abiogenic peptide mimic." Microbiology 152, no. 7 (July 1, 2006): 1913–18. http://dx.doi.org/10.1099/mic.0.28812-0.

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The human-mediated use and abuse of classical antibiotics has created a strong selective pressure for the rapid evolution of antibiotic resistance. As resistance levels rise, and the efficacy of classical antibiotics wanes, the intensity of the search for alternative antimicrobials has increased. One class of molecules that has attracted much attention is the antimicrobial peptides (AMPs). They exhibit broad-spectrum activity, they are potent and they are widespread as part of the innate defence system of both vertebrates and invertebrates. However, peptides are complex molecules that suffer from proteolytic degradation. The ability to capture the essential properties of antimicrobial peptides in simple easy-to-prepare molecules that are abiotic in origin and non-proteolytic offers many advantages. Mechanistic and structural knowledge of existing AMPs was used to design a novel compound that mimics the biochemical activity of an AMP. This report describes the development and in vitro characterization of a small peptide mimic that exhibited quick-acting and selective antibacterial activity against a broad range of bacteria, including numerous clinically relevant strains, at low MIC values.
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Findlay, Brandon, George G. Zhanel, and Frank Schweizer. "Cationic Amphiphiles, a New Generation of Antimicrobials Inspired by the Natural Antimicrobial Peptide Scaffold." Antimicrobial Agents and Chemotherapy 54, no. 10 (August 9, 2010): 4049–58. http://dx.doi.org/10.1128/aac.00530-10.

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ABSTRACT Naturally occurring cationic antimicrobial peptides (AMPs) and their mimics form a diverse class of antibacterial agents currently validated in preclinical and clinical settings for the treatment of infections caused by antimicrobial-resistant bacteria. Numerous studies with linear, cyclic, and diastereomeric AMPs have strongly supported the hypothesis that their physicochemical properties, rather than any specific amino acid sequence, are responsible for their microbiological activities. It is generally believed that the amphiphilic topology is essential for insertion into and disruption of the cytoplasmic membrane. In particular, the ability to rapidly kill bacteria and the relative difficulty with which bacteria develop resistance make AMPs and their mimics attractive targets for drug development. However, the therapeutic use of naturally occurring AMPs is hampered by the high manufacturing costs, poor pharmacokinetic properties, and low bacteriological efficacy in animal models. In order to overcome these problems, a variety of novel and structurally diverse cationic amphiphiles that mimic the amphiphilic topology of AMPs have recently appeared. Many of these compounds exhibit superior pharmacokinetic properties and reduced in vitro toxicity while retaining potent antibacterial activity against resistant and nonresistant bacteria. In summary, cationic amphiphiles promise to provide a new and rich source of diverse antibacterial lead structures in the years to come.
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44

Wang, Guangshun, Raquel F. Epand, Biswajit Mishra, Tamara Lushnikova, Vinai Chittezham Thomas, Kenneth W. Bayles, and Richard M. Epand. "Decoding the Functional Roles of Cationic Side Chains of the Major Antimicrobial Region of Human Cathelicidin LL-37." Antimicrobial Agents and Chemotherapy 56, no. 2 (November 14, 2011): 845–56. http://dx.doi.org/10.1128/aac.05637-11.

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ABSTRACTHuman cathelicidin LL-37 is a critical cationic antimicrobial peptide for host defense against infection, immune modulation, and wound healing. This article elucidates the functional roles of the cationic side chains of the major antimicrobial region of LL-37, corresponding to residues 17 to 32 (designated GF-17). Antimicrobial assays, killing kinetics studies, and vesicle leakage experiments all indicate that a conversion of lysines to arginines affected the ability of the peptide to kill the Gram-positiveStaphylococcus aureusstrain USA300. Alanine scanning experiments show thatS. aureusis less sensitive thanEscherichia colito a single cationic residue mutation of GF-17. Among the five cationic residues, R23 appears to be somewhat important in killingS. aureus. However, R23 and K25 of GF-17 are of prime importance in killing the Gram-negative organismE. coli. In particular, R23 is essential for (i) rapid recognition, (ii) permeation of theE. coliouter membrane, (iii) clustering of anionic lipids in a membrane system mimicking theE. coliinner membrane, and (iv) membrane disruption. Bacterial aggregation (i.e., rapid recognition via charge neutralization) is the first step of the peptide action. Structurally, R23 is located in the interface (i.e., the first action layer), a situation ideal for the interactions listed above. In contrast, residues K18, R19, and R29 are on the hydrophilic surface of the amphipathic helix and play only a secondary role. Mapping of the functional spectrum of cationic residues of GF-17 provides a solid basis for engineering bacterium-specific antimicrobials using this highly potent template.
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45

Vakhrusheva, Tatyana V., Alexey V. Sokolov, Grigoriy D. Moroz, Valeria A. Kostevich, Nikolay P. Gorbunov, Igor P. Smirnov, Ekaterina N. Grafskaia, Ivan A. Latsis, Oleg M. Panasenko, and Vassili N. Lazarev. "Effects of Synthetic Short Cationic Antimicrobial Peptides on the Catalytic Activity of Myeloperoxidase, Reducing Its Oxidative Capacity." Antioxidants 11, no. 12 (December 7, 2022): 2419. http://dx.doi.org/10.3390/antiox11122419.

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Cationic antimicrobial peptides (CAMPs) have gained attention as promising antimicrobial therapeutics causing lower or no bacterial resistance. Considerable achievements have been made in designing new CAMPs that are highly active as antimicrobials. However, there is a lack of research on their interaction with biologically important proteins. This study focused on CAMPs’ effects on myeloperoxidase (MPO), an enzyme which is microbicidal and concomitantly damaging to host biomolecules and cells due to its ability to produce reactive oxygen and halogen species (ROS/RHS). Four CAMPs designed by us were employed. MPO catalytic activity was assessed by an absorbance spectra analysis and by measuring enzymatic activity using Amplex Red- and Celestine Blue B-based assays. The peptide Hm-AMP2 accelerated MPO turnover. Pept_1545 and Hm-AMP8 inhibited both the MPO chlorinating and peroxidase activities, with components of different inhibition types. Hm-AMP8 was a stronger inhibitor. Its Ki towards H2O2 and Cl– was 0.3–0.4 μM vs. 11–20 μM for pept_1545. Peptide tyrosine and cysteine residues were involved in the mechanisms of the observed effects. The results propose a possible dual role of CAMPs as both antimicrobial agents and agents that downregulate MPO activation, and suggest CAMPs as prototypes for the development of antioxidant compounds to prevent MPO-mediated ROS/RHS overproduction.
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46

Vázquez, Roberto, Mateo Seoane-Blanco, Virginia Rivero-Buceta, Susana Ruiz, Mark J. van Raaij, and Pedro García. "Monomodular Pseudomonas aeruginosa phage JG004 lysozyme (Pae87) contains a bacterial surface-active antimicrobial peptide-like region and a possible substrate-binding subdomain." Acta Crystallographica Section D Structural Biology 78, no. 4 (March 4, 2022): 435–54. http://dx.doi.org/10.1107/s2059798322000936.

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Phage lysins are a source of novel antimicrobials to tackle the bacterial antibiotic-resistance crisis. The engineering of phage lysins is being explored as a game-changing technological strategy to introduce a more precise approach in the way in which antimicrobial therapy is applied. Such engineering efforts will benefit from a better understanding of lysin structure and function. In this work, the antimicrobial activity of the endolysin from Pseudomonas aeruginosa phage JG004, termed Pae87, has been characterized. This lysin had previously been identified as an antimicrobial agent candidate that is able to interact with the Gram-negative surface and disrupt it. Further evidence is provided here based on a structural and biochemical study. A high-resolution crystal structure of Pae87 complexed with a peptidoglycan fragment showed a separate substrate-binding region within the catalytic domain, 18 Å away from the catalytic site and located on the opposite side of the lysin molecule. This substrate-binding region was conserved among phylogenetically related lysins lacking an additional cell-wall-binding domain, but not among those containing such a module. Two glutamic acids were identified to be relevant for the peptidoglycan-degradation activity, although the antimicrobial activity of Pae87 was seemingly unrelated. In contrast, an antimicrobial peptide-like region within the Pae87 C-terminus, named P87, was found to be able to actively disturb the outer membrane and display antibacterial activity by itself. Therefore, an antimicrobial mechanism for Pae87 is proposed in which the P87 peptide plays the role of binding to the outer membrane and disrupting the cell-wall function, either with or without the participation of the catalytic activity of Pae87.
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47

Baek, Mihwa, Masakatsu Kamiya, Taichi Nakazumi, Satoshi Tomisawa, Yasuhiro Kumaki, Takashi Kikukawa, Makoto Demura, Keiichi Kawano, and Tomoyasu Aizawa. "3P011 Structural analysis of antimicrobial peptide CP1 with LPS by NMR(01A. Protein: Structure,Poster)." Seibutsu Butsuri 53, supplement1-2 (2013): S213. http://dx.doi.org/10.2142/biophys.53.s213_5.

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48

Frimodt-Møller, Jakob, Christopher Campion, Peter E. Nielsen, and Anders Løbner-Olesen. "Translocation of non-lytic antimicrobial peptides and bacteria penetrating peptides across the inner membrane of the bacterial envelope." Current Genetics 68, no. 1 (November 8, 2021): 83–90. http://dx.doi.org/10.1007/s00294-021-01217-9.

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AbstractThe increase in multidrug-resistant pathogenic bacteria has become a problem worldwide. Currently there is a strong focus on the development of novel antimicrobials, including antimicrobial peptides (AMP) and antimicrobial antisense agents. While the majority of AMP have membrane activity and kill bacteria through membrane disruption, non-lytic AMP are non-membrane active, internalize and have intracellular targets. Antimicrobial antisense agents such as peptide nucleic acids (PNA) and phosphorodiamidate morpholino oligomers (PMO), show great promise as novel antibacterial agents, killing bacteria by inhibiting translation of essential target gene transcripts. However, naked PNA and PMO are unable to translocate across the cell envelope of bacteria, to reach their target in the cytosol, and are conjugated to bacteria penetrating peptides (BPP) for cytosolic delivery. Here, we discuss how non-lytic AMP and BPP-PMO/PNA conjugates translocate across the cytoplasmic membrane via receptor-mediated transport, such as the cytoplasmic membrane transporters SbmA, MdtM/YjiL, and/or YgdD, or via a less well described autonomous process.
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49

Hayashi, Katsuhiko, Takashi Misawa, Chihiro Goto, Yosuke Demizu, Yukiko Hara-Kudo, and Yutaka Kikuchi. "The effects of magainin 2-derived and rationally designed antimicrobial peptides on Mycoplasma pneumoniae." PLOS ONE 17, no. 1 (January 24, 2022): e0261893. http://dx.doi.org/10.1371/journal.pone.0261893.

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Combating the spread of antimicrobial resistance (AMR) among bacteria requires a new class of antimicrobials, which desirably have a narrow spectrum because of their low propensity for the spread of AMR. Antimicrobial peptides (AMPs), which target the bacterial cell membrane, are promising seeds for novel antimicrobials because the cell membrane is essential for all cells. Previously, we reported the antimicrobial and haemolytic effects of a natural AMP, magainin 2 (Mag2), isolated from the skin of Xenopus laevis (the African clawed frog), four types of synthesised Mag2 derivatives, and three types of rationally designed AMPs on gram-positive and gram-negative bacteria. To identify novel antimicrobial seeds, we evaluated the effect of AMPs on Mycoplasma pneumoniae, which also exhibits AMR. We also evaluated the antimicrobial effects of an AMP, NK2A, which has been reported to have antimicrobial effects on Mycoplasma bovis, in addition to Mag2 and previously synthesised seven AMPs, on four strains of M. pneumoniae using colorimetric, biofilm, and killing assays. We found that three synthesised AMPs, namely 17base-Ac6c, 17base-Hybrid, and Block, had anti-M. pneumoniae (anti-Mp) effect at 8–30 μM, whereas others, including NK2A, did not have any such effect. For the further analysis, the membrane disruption activities of AMPs were measured by propidium iodide (PI) uptake assays, which suggested the direct interaction of AMPs to the cell membrane basically following the colorimetric, biofilm, and killing assay results. PI uptake assay, however, also showed the NK2A strong interaction to cell membrane, indicating unknown anti-Mp determinant factors related to the peptide sequences. Finally, we conclude that anti-Mp effect was not simply determined by the membrane disruption activities of AMPs, but also that the sequence of AMPs were important for killing of M. pneumoniae. These findings would be helpful for the development of AMPs for M. pneumoniae.
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50

Neubauer, Damian, Maciej Jaśkiewicz, Marta Bauer, Agata Olejniczak-Kęder, Emilia Sikorska, Karol Sikora, and Wojciech Kamysz. "Biological and Physico-Chemical Characteristics of Arginine-Rich Peptide Gemini Surfactants with Lysine and Cystine Spacers." International Journal of Molecular Sciences 22, no. 7 (March 24, 2021): 3299. http://dx.doi.org/10.3390/ijms22073299.

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Ultrashort cationic lipopeptides (USCLs) and gemini cationic surfactants are classes of potent antimicrobials. Our recent study has shown that the branching and shortening of the fatty acids chains with the simultaneous addition of a hydrophobic N-terminal amino acid in USCLs result in compounds with enhanced selectivity. Here, this approach was introduced into arginine-rich gemini cationic surfactants. l-cystine diamide and l-lysine amide linkers were used as spacers. Antimicrobial activity against planktonic and biofilm cultures of ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) strains and Candida sp. as well as hemolytic and cytotoxic activities were examined. Moreover, antimicrobial activity in the presence of human serum and the ability to form micelles were evaluated. Membrane permeabilization study, serum stability assay, and molecular dynamics were performed. Generally, critical aggregation concentration was linearly correlated with hydrophobicity. Gemini surfactants were more active than the parent USCLs, and they turned out to be selective antimicrobial agents with relatively low hemolytic and cytotoxic activities. Geminis with the l-cystine diamide spacer seem to be less cytotoxic than their l-lysine amide counterparts, but they exhibited lower antibiofilm and antimicrobial activities in serum. In some cases, geminis with branched fatty acid chains and N-terminal hydrophobic amino acid resides exhibited enhanced selectivity to pathogens over human cells.
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