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https://www.readbyqxmd.com/read/28437109/structure-of-the-fundamental-lipopeptide-surfactin-at-the-air-water-interface-investigated-by-sum-frequency-generation-spectroscopy
#1
Sami Alhassan Goussous, Michael Thomas Lee Casford, Annabel C Murphy, George Salmond, Finian J Leeper, Paul B Davies
The lipopeptide surfactin produced by certain strains of Bacillus subtilis is a powerful bio-surfactant possessing potentially useful antimicrobial properties. In order to better understand its surface behaviour, we have used surface sensitive Sum Frequency Generation (SFG) vibrational spectroscopy in the C-H and C=O stretching regions to determine its structure at the air/water interface. Using surfactin with the leucine groups of the peptide ring perdeuterated we have shown that the majority of the SFG signals arise from the 4 leucine residues...
April 24, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28432441/direct-quantification-of-lipopeptide-biosurfactants-in-biological-samples-via-hplc-and-uplc-ms-requires-sample-modification-with-an-organic-solvent
#2
Piotr Biniarz, Marcin Łukaszewicz
The rapid and accurate quantification of biosurfactants in biological samples is challenging. In contrast to the orcinol method for rhamnolipids, no simple biochemical method is available for the rapid quantification of lipopeptides. Various liquid chromatography (LC) methods are promising tools for relatively fast and exact quantification of lipopeptides. Here, we report strategies for the quantification of the lipopeptides pseudofactin and surfactin in bacterial cultures using different high- (HPLC) and ultra-performance liquid chromatography (UPLC) systems...
April 22, 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28428684/innate-immunity-of-adipose-tissue-in-rodent-models-of-local-and-systemic-staphylococcus-aureus-infection
#3
Andreas Schmid, Thomas Karrasch, Miriam Thomalla, Jutta Schlegel, Bernd Salzberger, Andreas Schäffler, Frank Hanses
Background. The role of adipose tissue in systemic inflammation during bacterial infection is unclear. Effects of Staphylococcus aureus infection on adipocytes in rodent models of experimental endocarditis and peritonitis, the impact of S. aureus infection on gene expression in epididymal and subcutaneous adipose tissue, and effects of S. aureus infection on the toll-like receptor-2- (TLR2-) cathelicidin pathway in vivo and in vitro were investigated. Material and methods. The rat model of catheter-induced S...
2017: Mediators of Inflammation
https://www.readbyqxmd.com/read/28421168/contribution-of-the-a-baumannii-a1s_0114-gene-to-the-interaction-with-eukaryotic-cells-and-virulence
#4
Soraya Rumbo-Feal, Astrid Pérez, Theresa A Ramelot, Laura Álvarez-Fraga, Juan A Vallejo, Alejandro Beceiro, Emily J Ohneck, Brock A Arivett, María Merino, Steven E Fiester, Michael A Kennedy, Luis A Actis, Germán Bou, Margarita Poza
Genetic and functional studies showed that some components of the Acinetobacter baumannii ATCC 17978 A1S_0112-A1S_0119 gene cluster are critical for biofilm biogenesis and surface motility. Recently, our group has shown that the A1S_0114 gene was involved in biofilm formation, a process related with pathogenesis. Confirming our previous results, microscopy images revealed that the ATCC 17978 Δ0114 derivative lacking this gene was unable to form a mature biofilm structure. Therefore, other bacterial phenotypes were analyzed to determine the role of this gene in the pathogenicity of A...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28419983/pam3csk4-induces-mmp-9-expression-in-human-monocytic-thp-1-cells
#5
Fatema Al-Rashed, Shihab Kochumon, Safa Usmani, Sardar Sindhu, Rasheed Ahmad
BACKGROUND: Matrix metalloproteinase (MMP)-9 is known to degrade the extracellular matrix and increased MMP-9 levels are related with the pathogenesis of many inflammatory conditions including obesity. Pam3CSK4 is a synthetic triacylated lipopeptide (LP) which is a potent activator of immune cells and induces cytokine production. However, it is unclear whether Pam3CSK4 is able to induce MMP-9 expression in monocytic cells. We, therefore, determined MMP-9 production by Pam3CSK4-treated THP-1 cells and also investigated the signal transduction pathway(s) involved...
April 13, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28419973/antibacterial-antifungal-and-antimycobacterial-compounds-from-cyanobacteria
#6
REVIEW
Shasank S Swain, Sudhir K Paidesetty, Rabindra N Padhy
Infections from multidrug resistant (MDR) pathogenic bacteria, fungi and Mycobacterium tuberculosis remain progressively intractable. The search of effective antimicrobials from other possible non-conventional sources against MDR pathogenic bacteria, fungi and mycobacteria is call of the day. This review considers 121 cyanobacterial compounds or cyano-compounds with antimicrobial activities. Chemical structures of cyano-compounds were retrieved from ChemSpider and PubChem databases and were visualized by the software ChemDraw Ultra...
April 15, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28411538/formulation-of-crude-oil-spill-dispersants-based-on-the-hld-concept-and-using-a-lipopeptide-biosurfactant
#7
Witchaya Rongsayamanont, Suwat Soonglerdsongpha, Nichakorn Khondee, Onruthai Pinyakong, Chantra Tongcumpou, David A Sabatini, Ekawan Luepromchai
Solvent-free dispersants for crude oil spills were formulated based on the hydrophilic-lipophilic deviation (HLD) concept and using lipopeptides from Bacillus sp. GY19. The lipopeptides were recovered and concentrated from cell-free broth by foam fractionation and freeze-drying. They had good surface activity under varying temperatures, pH and NaCl levels. Moreover, the lipopeptides had low toxicity to copepods (LC50 1174mg/L) and whiteleg shrimp (LC50 1050mg/L). The characteristic curvature (Cc) of the lipopeptides showed that they were more hydrophobic (Cc 4...
April 4, 2017: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/28406518/a-multicomponent-macrocyclization-strategy-to-natural-product-like-cyclic-lipopeptides-synthesis-and-anticancer-evaluation-of-surfactin-and-mycosubtilin-analogues
#8
Micjel C Morejón, Annegret Laub, Goran N Kaluđerović, Alfredo R Puentes, Ali N Hmedat, Anselmo J Otero-González, Daniel G Rivera, Ludger A Wessjohann
A multicomponent macrocyclization strategy towards cyclic lipopeptides is described. The approach relies on the utilization of the Ugi and Passerini multicomponent reactions for the cyclization of peptides and oxo-peptides, and here it is employed for the construction of a small library of analogues of the natural products mycosubtilin and surfactin A. A key feature of this method is the simultaneous incorporation of either one or two exocyclic lipid tails along with the macrocyclic ring closure, which is only possible due to the multicomponent nature of the macrocyclization step...
April 13, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28404797/self-adjuvanting-c18-lipid-vinil-sulfone-pp2a-vaccine-study-of-the-induced-immunomodulation-against-trichuris-muris-infection
#9
M Gomez-Samblas, J J García-Rodríguez, M Trelis, D Bernal, F J Lopez-Jaramillo, F Santoyo-Gonzalez, S Vilchez, A M Espino, F Bolás-Fernández, A Osuna
Despite the importance of the adjuvant in the immunization process, very few adjuvants merge with the antigens in vaccines. A synthetic self-adjuvant oleic-vinyl sulfone (OVS) linked to the catalytic region of recombinant serine/threonine phosphatase 2A from the nematode Angiostrongylus costaricensis (rPP2A) was used for intranasal immunization in mice previously infected with Trichuris muris The animal intranasal immunization with rPP2A-OVS showed a reduction of 99.01% in the number of the nematode eggs and 97...
April 2017: Open Biology
https://www.readbyqxmd.com/read/28403559/integrin-receptor-targeting-rgdk-tagged-nanocarrier-anticancer-efficacy-of-loaded-curcumin
#10
Prasanta Kumar Das, Krishnendu Das, Sahithi Nimushakavi, Arabinda Chaudhuri
Herein we report the design and development of α5β1 integrin receptor specific RGDK-lipopeptide associated non-covalently dispersed single walled carbon nanotube (SWNT) that selectively deliver anti-cancer curcumin to tumor cells. Arg-Gly-Asp-Lys (RGDK) tetrapeptide tagged amphiphiles were synthesized that efficiently dispersed SWNT with >80% suspension stability index in cell culture media. MTT & LDH based cell viability assays in tumor (melanoma, B16F10) and non-cancerous (mouse fibroblast cells, NIH3T3) revealed non-cytotoxic nature of RGDK-lipopeptide-SWNT conjugates...
April 12, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28389850/production-and-partial-characterization-of-biosurfactant-produced-by-streptomyces-sp-r1
#11
Nor Syafirah Zambry, Adilah Ayoib, Nur Asshifa Md Noh, Ahmad Ramli Mohd Yahya
The present study focused on developing a wild-type actinomycete isolate as a model for a non-pathogenic filamentous producer of biosurfactants. A total of 33 actinomycetes isolates were screened and their extracellular biosurfactants production was evaluated using olive oil as the main substrate. Out of 33 isolates, 32 showed positive results in the oil spreading technique (OST). All isolates showed good emulsification activity (E24) ranging from 84.1 to 95.8%. Based on OST and E24 values, isolate R1 was selected for further investigation in biosurfactant production in an agitated submerged fermentation...
April 7, 2017: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/28389538/pumilacidin-like-lipopeptides-derived-from-marine-bacterium-bacillus-sp-suppress-the-motility-of-vibrio-alginolyticus
#12
Pengyuan Xiu, Rui Liu, Dechao Zhang, Chaomin Sun
Bacterial motility is a crucial factor during the invasion and colonization processes of pathogens, which makes it an attractive therapeutic drug target. Here, we isolated a marine bacterium (Vibrio alginolyticus 178) from a seamount in the tropical West Pacific that exhibits vigorous motility on agar plates and severe pathogenicity to zebrafish. We found that V. alginolyticus 178 motility was significantly suppressed by another marine bacterium Bacillus sp. 176 isolated from the same niche. We isolated, purified, and characterized two different cyclic lipopeptides (CLPs) from Bacillus sp...
April 7, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28374588/detection-of-the-lipopeptide-pam3csk4-using-a-hybridized-toll-like-receptor-electrochemical-sensor
#13
Zhe She, Kristin Topping, Tianxiao Ma, Tiantian Zhao, Wenxia Zhou, Ajar Kamal, Soha Ahmadi, Heinz-Bernhard Kraatz
Electrochemical detection of Pam3CSK4, a synthetic triacylated lipopeptide that mimics the structural moieties of its natural Gram negative bacterial pathogen-associated molecular pattern (PAMP) counterpart, has been achieved using hybridized toll-like receptors (TLR) combining TLR1 and TLR2 onto a single sensor surface. These sensors represent the first hybridized TLR sensors. The limit of detection for Pam3CSK4 attained was 7.5 μg/mL, which is within the same order of magnitude for that of the more labor-intensive and time-consuming cell-assay technique, 2...
April 12, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28374547/improvement-of-iturin-a-production-in-bacillus-subtilis-zk0-by-overexpression-of-the-coma-and-siga-genes
#14
Z Zhang, Z T Ding, J Zhong, J Y Zhou, D Shu, D Luo, J Yang, H Tan
Bacillus subtilis ZK0, which was isolated from cotton, produces a type of lipopeptide antibiotic iturin A that inhibits the growth of pathogenic fungi on agricultural crops. However, the low level of iturin A production by B. subtilis ZK0 does not support its large-scale application. In this study, B. subtilis ZK0 was subjected to genetic manipulation to improve iturin A production. By the independent or simultaneous overexpression of two regulatory genes (comA and sigA), iturin A production by B. subtilis ZK0 was significantly increased...
April 4, 2017: Letters in Applied Microbiology
https://www.readbyqxmd.com/read/28372863/recycling-of-carbon-dioxide-by-free-air-co2-enriched-face-bacillus-sp-ss105-for-enhanced-production-and-optimization-of-biosurfactant
#15
Neha Maheshwari, Madan Kumar, Indu Shekhar Thakur, Shaili Srivastava
Carbon dioxide utilizing bacterium Bacillus sp. SS105 was isolated from FACE (free air CO2 enriched) sample. The strain was grown in shake flask containing minimal salt medium with 50mM NaHCO3 as autotrophic carbon source and molasses as a low cost byproduct for mixotrophic growth. Carbon dioxide sequestration property of Bacillus sp. SS105 was determined by enzyme assay of carbonic anhydrase and ribulose-1, 5-bisphosphate carboxylase/oxygenase (RuBisCO). Along with CO2 sequestration this strain produced biosurfactant and its characterization by FTIR and (1)H NMR indicated lipopeptide nature...
March 24, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28371347/genetic-engineering-of-the-branched-fatty-acid-metabolic-pathway-of-bacillus-subtilis-for-the-overproduction-of-surfactin-c14-isoform
#16
Debarun Dhali, François Coutte, Anthony Argüelles Arias, Sandrine Auger, Vladimir Bidnenko, Gabrielle Chataigné, Michael Lalk, Joachim Niehren, Joana de Sousa, Cristian Versari, Philippe Jacques
Surfactin, a lipopeptide produced by Bacillus subtilis, is one of the most powerful biosurfactants known. This molecule consists of a cyclic heptapeptide linked to a β-hydroxy fatty acid chain. The isomery and the length of the fatty acid (FA) chain are responsible for the surfactin's activities. In this study, the gene codY, which encode for the global transcriptional regulator and the gene lpdV, located in the bkd operon (lpdV, bkdAA, bkdAB and bkdB genes), which is responsible for the last step of the branched chain amino acid (BCAA) degradation in acyl-CoA were deleted...
April 3, 2017: Biotechnology Journal
https://www.readbyqxmd.com/read/28368065/synthesis-sar-and-biological-studies-of-sugar-amino-acid-based-almiramide-analogues-n-methylation-leads-the-way
#17
Dipendu Das, Hina P A Khan, Rahul Shivahare, Suman Gupta, Jayanta Sarkar, Mohd Imran Siddiqui, Ravi Sankar Ampapathi, Tushar Kanti Chakraborty
Leishmaniasis, caused by the protozoan parasites of the genus Leishmania, is one of the most neglected diseases endemic in many continents posing enormous global health threats and therefore the discovery of new antileishmanial compounds is of utmost urgency. The antileishmanial activities of a library of sugar amino acid-based linear lipopeptide analogues were examined with the aim to identify potential drug candidates to treat visceral leishmaniasis. It was found that among the synthesized analogues, most of the permethylated compounds exhibited more activity in in vitro studies against intra-macrophagic amastigotes than the non-methylated analogues...
April 11, 2017: Organic & Biomolecular Chemistry
https://www.readbyqxmd.com/read/28367578/inclusion-of-lipopeptides-into-the-dmpc-lipid-bilayers-prevents-a%C3%AE-peptide-insertion
#18
Niyati Parikh, Dmitri K Klimov
Using an all-atom explicit water model and replica exchange with solute tempering molecular dynamics we have studied the binding of Aβ10-40 peptides to the mixed cationic bilayers composed of DMPC lipids and C14-KAAK lipopeptides (LPs). Using as a control our previous replica exchange simulations probing binding of the same peptide to the zwitterionic DMPC bilayer we assessed the impact of lipopeptides on the Aβ binding mechanism. We found that binding to the mixed DMPC + LP bilayers does not enhance the Aβ helix propensity as much as binding to the pure DMPC bilayers...
April 12, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28356533/a-lipopeptide-hiv-1-2-fusion-inhibitor-with-highly-potent-in-vitro-ex-vivo-and-in-vivo-antiviral-activity
#19
Huihui Chong, Jing Xue, Shengwen Xiong, Zhe Cong, Xiaohui Ding, Yuanmei Zhu, Zixuan Liu, Ting Chen, Yifan Feng, Lei He, Yan Guo, Qiang Wei, Yusen Zhou, Chuan Qin, Yuxian He
Peptides derived from the C-terminal heptad repeat (CHR) region of the HIV-1 fusogenic protein gp41 are potent viral entry inhibitors, and currently enfuvirtide (T-20) is the only one for clinical use; however, emerging drug-resistance largely limits its efficacy. In this study, we generated a novel lipopeptide inhibitor, named LP-19, by integrating multiple design strategies, including an N-terminal M-T hook structure, HIV-2 sequence, intra-helical salt-bridges, and a membrane-anchoring lipid tail. LP-19 showed stable binding affinity and highly potent, broad and long-lasting antiviral activity...
March 29, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28350438/an-acyl-linked-dimer-of-daptomycin-is-strongly-inhibited-by-the-bacterial-cell-wall
#20
Robert M Taylor, Bradley Scott, Scott Taylor, Michael Palmer
The lipopeptide antibiotic daptomycin is active against Gram-positive pathogens. It permeabilizes bacterial cell membranes, which involves the formation of membrane-associated oligomers. We here studied a dimer of daptomycin whose two subunits were linked through a bivalent aliphatic acyl chain. Unexpectedly, the dimer had very low activity on vegetative Staphylococcus aureus and Bacillus subtilis cells. However, activity resembled that of monomeric daptomycin on liposomes and on B. subtilis L-forms. These findings underscore the importance of the bacterial cell wall in daptomycin resistance...
March 28, 2017: ACS Infectious Diseases
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