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Model amphipathic peptide

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https://www.readbyqxmd.com/read/28798159/as-cath1-6-novel-cathelicidins-with-potent-antimicrobial-and-immunomodulatory-properties-from-alligator-sinensis-play-pivotal-roles-in-host-antimicrobial-immune-responses
#1
Yan Chen, Shasha Cai, Xue Qiao, Mali Wu, Zhilai Guo, Renping Wang, Yi-Qun Kuang, Haining Yu, Yipeng Wang
Crocodilians are regarded as possessing a powerful immune system. However, the composition and action of the crocodilian immune system have remained unclear until now. Cathelicidins, the principal family of host defense peptides, play pivotal roles in vertebrate immune defense against microbial invasions. However, cathelicidins from crocodilians have not been extensively studied to date. In the present study, six novel cathelicidins (As-CATH1-6) were identified and characterized from the endangered Chinese alligator (Alligator sinensis)...
August 10, 2017: Biochemical Journal
https://www.readbyqxmd.com/read/28726635/as-cath1-6-novel-cathelicidins-with-potent-antimicrobial-and-immunomodulatory-properties-from-alligator-sinensis-play-pivotal-roles-in-host-anti-microbial-immune-responses
#2
Yan Chen, Shasha Cai, Xue Qiao, Mali Wu, Zhilai Guo, Renping Wang, Yi-Qun Kuang, Haining Yu, Yipeng Wang
Crocodilians are regarded as possessing a powerful immune system. However, the composition and action of crocodilian immune system has remained unclear until now. Cathelicidins, the principal family of host defense peptides, play pivotal roles in vertebrate immune defense against microbial invasions. However, cathelicidins from crocodilians have not been extensively studied to date. In the present study, six novel cathelicidins (As-CATH1~6) were identified and characterized from the endangered Chinese Alligator ( Alligator sinensis )...
July 18, 2017: Biochemical Journal
https://www.readbyqxmd.com/read/28583830/probing-the-disparate-effects-of-arginine-and-lysine-residues-on-antimicrobial-peptide-bilayer-association
#3
A Rice, J Wereszczynski
Antimicrobial peptides (AMPs) are key components of the innate immune response and represent promising templates for the development of broad-spectrum alternatives to conventional antibiotics. Most AMPs are short, cationic peptides that interact more strongly with negatively charged prokaryotic membranes than net neutral eukaryotic ones. Both AMPs and synthetic analogues with arginine-like side chains are more active against bacteria than those with lysine-like amine groups, though the atomistic mechanism for this increase in potency remains unclear...
June 3, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28479275/effect-of-tacticity-derived-topological-constraints-in-bactericidal-peptides
#4
Prakash Kishore Hazam, Gaurav Jerath, Anil Kumar, Nitin Chaudhary, Vibin Ramakrishnan
Topology is a key element in structure-activity relationship estimation while designing physiologically-active molecular constructs. Peptides may be a preferred choice for therapeutics, principally due to their biocompatibility, low toxicity and predictable metabolism. Peptide design only guarantees functional group constitution by opting specific amino acid sequence, and not their spatial orientation to bind and incite physiological response on chosen targets. This is principally because peptide conformation is subject to external flux, due to the isotactic stereochemistry of the peptide chain...
May 4, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28470277/characterizing-the-structure-function-relationship-reveals-the-mode-of-action-of-a-novel-antimicrobial-peptide-p1-from-jumper-ant-myrmecia-pilosula
#5
Tien-Sheng Tseng, Keng-Chang Tsai, Chinpan Chen
Microbial infections of antibiotic-resistant strains cause serious diseases and have a significant impact on public health worldwide, so novel antimicrobial drugs are urgently needed. Insect venoms, a rich source of bioactive components containing antimicrobial peptides (AMPs), are attractive candidates for new therapeutic agents against microbes. Recently, a novel peptide, P1, identified from the venom of the Australian jumper ant Myrmecia pilosula, showed potent antimicrobial activities against both Gram-negative and Gram-positive bacteria, but its structure-function relationship is unknown...
May 4, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28459565/membrane-disruption-mechanism-of-a-prion-peptide-106-126-investigated-by-atomic-force-microscopy-raman-and-electron-paramagnetic-resonance-spectroscopy
#6
Jianjun Pan, Prasana K Sahoo, Annalisa Dalzini, Zahra Hayati, Chinta M Aryal, Peng Teng, Jianfeng Cai, Humberto Rodriguez Gutierrez, Likai Song
A fragment of the human prion protein spanning residues 106-126 (PrP106-126) recapitulates many essential properties of the disease-causing protein such as amyloidogenicity and cytotoxicity. PrP106-126 has an amphipathic characteristic that resembles many antimicrobial peptides (AMPs). Therefore, the toxic effect of PrP106-126 could arise from a direct association of monomeric peptides with the membrane matrix. Several experimental approaches are employed to scrutinize the impacts of monomeric PrP106-126 on model lipid membranes...
May 10, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28429592/peptide-retention-time-prediction-in-hydrophilic-interaction-liquid-chromatography-data-collection-methods-and-features-of-additive-and-sequence-specific-models
#7
Oleg V Krokhin, Peyman Ezzati, Vic Spicer
The development of a peptide retention prediction model for hydrophilic interaction liquid chromatography (XBridge Amide column) is described for a collection of ∼40 000 tryptic peptides. Off-line 2D LC-MS/MS analysis (HILIC-RPLC) of S. cerevisiae whole cell lysate has been used to acquire retention information for a HILIC separation. The large size of the optimization data set (more than 2 orders of magnitude compared to previous reports) permits the accurate assignment of hydrophilic retention coefficients of individual amino acids, establishing both the effects of amino acid position relative to peptide termini and the influence of peptide secondary structure in HILIC...
April 26, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28411186/direct-antimicrobial-activity-of-ifn-%C3%AE
#8
Amber Kaplan, Michelle W Lee, Andrea J Wolf, Jose J Limon, Courtney A Becker, Minna Ding, Ramachandran Murali, Ernest Y Lee, George Y Liu, Gerard C L Wong, David M Underhill
Type I IFNs are a cytokine family essential for antiviral defense. More recently, type I IFNs were shown to be important during bacterial infections. In this article, we show that, in addition to known cytokine functions, IFN-β is antimicrobial. Parts of the IFN-β molecular surface (especially helix 4) are cationic and amphipathic, both classic characteristics of antimicrobial peptides, and we observed that IFN-β can directly kill Staphylococcus aureus Further, a mutant S. aureus that is more sensitive to antimicrobial peptides was killed more efficiently by IFN-β than was the wild-type S...
May 15, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28358840/a-tetrameric-peptide-derived-from-bovine-lactoferricin-as-a-potential-therapeutic-tool-for-oral-squamous-cell-carcinoma-a-preclinical-model
#9
Víctor Alfonso Solarte, Paulette Conget, Jean-Paul Vernot, Jaiver Eduardo Rosas, Zuly Jenny Rivera, Javier Eduardo García, Martha Ligia Arango-Rodríguez
Oral squamous cell carcinoma is the fifth most common epithelial cancer in the world, and its current clinical treatment has both low efficiency and poor selectivity. Cationic amphipathic peptides have been proposed as new drugs for the treatment of different types of cancer. The main goal of the present work was to determine the potential of LfcinB(20-25)4, a tetrameric peptide based on the core sequence RRWQWR of bovine lactoferricin LfcinB(20-25), for the treatment of OSCC. In brief, OSCC was induced in the buccal pouch of hamsters by applying 7,12-Dimethylbenz(a)anthracene, and tumors were treated with one of the following peptides: LfcinB(20-25)4, LfcinB(20-25), or vehicle (control)...
2017: PloS One
https://www.readbyqxmd.com/read/28356384/il-26-confers-proinflammatory-properties-to-extracellular-dna
#10
Caroline Poli, Jean François Augusto, Jonathan Dauvé, Clément Adam, Laurence Preisser, Vincent Larochette, Pascale Pignon, Ariel Savina, Simon Blanchard, Jean François Subra, Alain Chevailler, Vincent Procaccio, Anne Croué, Christophe Créminon, Alain Morel, Yves Delneste, Helmut Fickenscher, Pascale Jeannin
In physiological conditions, self-DNA released by dying cells is not detected by intracellular DNA sensors. In chronic inflammatory disorders, unabated inflammation has been associated with a break in innate immune tolerance to self-DNA. However, extracellular DNA has to complex with DNA-binding molecules to gain access to intracellular DNA sensors. IL-26 is a member of the IL-10 cytokine family, overexpressed in numerous chronic inflammatory diseases, in which biological activity remains unclear. We demonstrate in this study that IL-26 binds to genomic DNA, mitochondrial DNA, and neutrophil extracellular traps, and shuttles them in the cytosol of human myeloid cells...
May 1, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
https://www.readbyqxmd.com/read/28339206/utilizing-electron-spin-echo-envelope-modulation-to-distinguish-between-the-local-secondary-structures-of-an-%C3%AE-helix-and-an-amphipathic-310-helical-peptide
#11
Lauren Bottorf, Sophia Rafferty, Indra D Sahu, Robert M McCarrick, Gary A Lorigan
Electron spin echo envelope modulation (ESEEM) spectroscopy was used to distinguish between the local secondary structures of an α-helix and a 310-helix. Previously, we have shown that ESEEM spectroscopy in combination with site-directed spin labeling (SDSL) and (2)H-labeled amino acids (i) can probe the local secondary structure of α-helices, resulting in an obvious deuterium modulation pattern, where i+4 positions generally show larger (2)H ESEEM peak intensities than i+3 positions. Here, we have hypothesized that due to the unique turn periodicities of an α-helix (3...
March 31, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28319176/insight-into-the-mechanism-of-action-of-temporin-sha-a-new-broad-spectrum-antiparasitic-and-antibacterial-agent
#12
Zahid Raja, Sonia André, Feten Abbassi, Vincent Humblot, Olivier Lequin, Tahar Bouceba, Isabelle Correia, Sandra Casale, Thierry Foulon, Denis Sereno, Bruno Oury, Ali Ladram
Antimicrobial peptides (AMPs) are promising drugs to kill resistant pathogens. In contrast to bacteria, protozoan parasites, such as Leishmania, were little studied. Therefore, the antiparasitic mechanism of AMPs is still unclear. In this study, we sought to get further insight into this mechanism by focusing our attention on temporin-SHa (SHa), a small broad-spectrum AMP previously shown to be active against Leishmania infantum. To improve activity, we designed analogs of SHa and compared the antibacterial and antiparasitic mechanisms...
2017: PloS One
https://www.readbyqxmd.com/read/28236791/lipid-selectivity-in-novel-antimicrobial-peptides-implication-on-antimicrobial-and-hemolytic-activity
#13
P Maturana, M Martinez, M E Noguera, N C Santos, E A Disalvo, L Semorile, P C Maffia, A Hollmann
Antimicrobial peptides (AMPs) are small cationic molecules that display antimicrobial activity against a wide range of bacteria, fungi and viruses. For an AMP to be considered as a therapeutic option, it must have not only potent antibacterial properties but also low hemolytic and cytotoxic activities [1]. Even though many studies have been conducted in order to correlate the antimicrobial activity with affinity toward model lipid membranes, the use of these membranes to explain cytotoxic effects (especially hemolysis) has been less explored...
May 1, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28196861/molecular-determinants-of-the-n-terminal-acetyltransferase-naa60-anchoring-to-the-golgi-membrane
#14
Henriette Aksnes, Marianne Goris, Øyvind Strømland, Adrian Drazic, Qaiser Waheed, Nathalie Reuter, Thomas Arnesen
Nα-Acetyltransferase 60 (Naa60 or NatF) was recently identified as an unconventional N-terminal acetyltransferase (NAT) because it localizes to organelles, in particular the Golgi apparatus, and has a preference for acetylating N termini of the transmembrane proteins. This knowledge challenged the prevailing view of N-terminal acetylation as a co-translational ribosome-associated process and suggested a new mechanistic functioning for the enzymes responsible for this increasingly recognized protein modification...
April 21, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28193076/integration-of-quartz-crystal-microbalance-dissipation-and-reflection-mode-localized-surface-plasmon-resonance-sensors-for-biomacromolecular-interaction-analysis
#15
Abdul Rahim Ferhan, Joshua A Jackman, Nam-Joon Cho
The combination of label-free, surface-sensitive measurement techniques based on different physical principles enables detailed characterization of biomacromolecular interactions at solid-liquid interfaces. To date, most combined measurement systems have involved experimental techniques with similar probing volumes, whereas the potential of utilizing techniques with different surface sensitivities remains largely unexplored, especially for data interpretation. Herein, we report a combined measurement approach that integrates a conventional quartz crystal microbalance-dissipation (QCM-D) setup with a reflection-mode localized surface plasmon (LSPR) sensor...
December 20, 2016: Analytical Chemistry
https://www.readbyqxmd.com/read/28138522/the-activation-loop-of-pip5k-functions-as-a-membrane-sensor-essential-for-lipid-substrate-processing
#16
Aizhuo Liu, Dexin Sui, Dianqing Wu, Jian Hu
Phosphatidylinositol 4-phosphate 5-kinase (PIP5K), a representative member of the phosphatidylinositol phosphate kinase (PIPK) family, is a major enzyme that biosynthesizes the signaling molecule PI(4,5)P2 (phosphatidylinositol 4,5-bisphosphate) in eukaryotic cells. The stringent specificity toward lipid substrates and the high sensitivity to the membrane environment strongly suggest a membrane-sensing mechanism, but the underlying structural basis is still largely unknown. We present a nuclear magnetic resonance (NMR) study on a peptide commensurate with a PIP5K's activation loop, which has been reported to be a determinant of lipid substrate specificity and subcellular localization of PIP5K...
November 2016: Science Advances
https://www.readbyqxmd.com/read/28126403/binding-of-amphipathic-cell-penetrating-peptide-p28-to-wild-type-and-mutated-p53-as-studied-by-raman-atomic-force-and-surface-plasmon-resonance-spectroscopies
#17
Sara Signorelli, Simona Santini, Tohru Yamada, Anna Rita Bizzarri, Craig W Beattie, Salvatore Cannistraro
BACKGROUND: Mutations within the DNA binding domain (DBD) of the tumor suppressor p53 are found in >50% of human cancers and may significantly modify p53 secondary structure impairing its function. p28, an amphipathic cell-penetrating peptide, binds to the DBD through hydrophobic interaction and induces a posttranslational increase in wildtype and mutant p53 restoring functionality. We use mutation analyses to explore which elements of secondary structure may be critical to p28 binding...
April 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28073163/hydrocarbon-stapled-lipopeptides-exhibit-selective-antimicrobial-activity
#18
Zachary B Jenner, Christopher M Crittenden, Martín Gonzalez, Jennifer S Brodbelt, Kerry A Bruns
Antimicrobial peptides (AMPs) occur widely in nature and have been studied for their therapeutic potential. AMPs are of interest due to the large number of possible chemical structural combinations using natural and unnatural amino acids, with varying effects on their biological activities. Using physicochemical properties from known naturally occurring amphipathic cationic AMPs, several hydrocarbon-stapled lipopeptides (HSLPs) were designed, synthesized, and tested for antimicrobial properties. Peptides were chemically modified by N-terminal acylation, C-terminal amidation, and some were hydrocarbon stapled by intramolecular olefin metathesis...
May 2017: Biopolymers
https://www.readbyqxmd.com/read/28068080/effect-of-the-southeast-asian-ovalocytosis-deletion-on-the-conformational-dynamics-of-signal-anchor-transmembrane-segment-1-of-red-cell-anion-exchanger-1-ae1-band-3-or-slc4a1
#19
Philip W Fowler, Mark S P Sansom, Reinhart A F Reithmeier
The first transmembrane (TM1) helix in the red cell anion exchanger (AE1, Band 3, or SLC4A1) acts as an internal signal anchor that binds the signal recognition particle and directs the nascent polypeptide chain to the endoplasmic reticulum (ER) membrane where it moves from the translocon laterally into the lipid bilayer. The sequence N-terminal to TM1 forms an amphipathic helix that lies at the membrane interface and is connected to TM1 by a bend at Pro403. Southeast Asian ovalocytosis (SAO) is a red cell abnormality caused by a nine-amino acid deletion (Ala400-Ala408) at the N-terminus of TM1...
February 7, 2017: Biochemistry
https://www.readbyqxmd.com/read/27951656/amphiphilicity-is-a-key-determinant-in-the-membrane-interactions-of-synthetic-14-mer-cationic-peptide-analogues
#20
Matthieu Fillion, Maxime Goudreault, Normand Voyer, Burkhard Bechinger, Michèle Auger
Cationic antimicrobial peptides are a component of the innate immune system of several organisms and represent an interesting alternative to fight multiresistant bacteria. In this context, we have elaborated a synthetic peptide scaffold allowing the study of the impact of different molecular determinants on the membrane interactions. The aim of the present study was to elucidate the mechanism of action of two cationic peptides that derive from a neutral 14-mer template peptide and where the hydrophilic portion is composed of a crown ether...
December 13, 2016: Biochemistry
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