Magainin 2 and PGLa are cationic, amphipathic antimicrobial peptides which when added as equimolar mixture exhibit a pronounced synergism in both their antibacterial and pore-forming activities. Here we show for the first time that the peptides assemble into defined supramolecular structures along the membrane interface. The resulting mesophases are quantitatively described by state-of-the art fluorescence self-quenching and correlation spectroscopies. Notably, the synergistic behavior of magainin 2 and PGLa correlates with the formation of hetero-domains and an order-of-magnitude increased membrane affinity of both peptides. Enhanced membrane association of the peptide mixture is only observed in the presence of phophatidylethanolamines but not of phosphatidylcholines, lipids that dominate bacterial and eukaryotic membranes, respectively. Thereby the increased membrane-affinity of the peptide mixtures not only explains their synergistic antimicrobial activity, but at the same time provides a new concept to increase the therapeutic window of combinatorial drugs.

• MeSH
• antibakteriální látky chemie   izolace a purifikace   farmakologie   MeSH
• buněčná membrána chemie   účinky léků   MeSH
• ethanolaminy chemie   MeSH
• fixní kombinace léků MeSH
• fluorescenční barviva chemie   MeSH
• fluorescenční spektrometrie MeSH
• fosfatidylcholiny chemie   MeSH
• fosfatidylethanolaminy chemie   MeSH
• fosfatidylglyceroly chemie   MeSH
• kationické antimikrobiální peptidy chemie   izolace a purifikace   farmakologie   MeSH
• kůže chemie   MeSH
• lipidové dvojvrstvy chemie   MeSH
• magaininy chemie   izolace a purifikace   farmakologie   MeSH
• proteiny Xenopus chemie   izolace a purifikace   farmakologie   MeSH
• sloučeniny boru chemie   MeSH
• synergismus léků MeSH
• vazba proteinů MeSH
• Xenopus laevis MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The strain Raoultella sp. KDF8 was cultivated on three sources of carbon and energy, glycerol, ethanol and diclofenac, for periods of time ranging from 24 to 72 h. Using thin-layer chromatography, nine classes of phospholipids were detected and the amount of phosphatidylethanolamine (PtdEtn) decreased with increasing cultivation time. Conversely, the ratio of phospholipids having three or four acyls (acyl-phosphatidylglycerol (APtdGro), N-acyl-PtdEtn (NAPtdEtn) and cardiolipin (Ptd2Gro) increased during cultivation. GC-MS analysis showed that the percentage of fatty acids containing a cyclopropane ring increased almost tenfold whereas the amount of fatty acids bearing even-numbered chains dropped to less than one-third after 24 h and 72 h in cultures on glycerol and diclofenac, respectively. Shotgun analysis showed significant changes in the representation of molecular species of phospholipids. For instance, there was a 36-fold change in the ratio of 16:1/16:1/16:1-APtdGro to c17:0/c17:0/c17:0-APtdGro and a 12-fold ratio change for 16:1/16:1/16:1-NAPtdEtn to c17:0/c17:0/c17:0-NAPtdEtn; the Ptd2Gro ratio of 16:1 to c17:0 acids equalled 1750. Our results show that the bacteria overcome destabilization of the inner cytoplasmic cell membrane and a bacterial outer membrane by altering the geometric arrangement of acyl chains, i.e. switching from monounsaturated to cyclopropane fatty acids (16:1 versus c17:0).

• MeSH
• antiflogistika farmakologie   MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• diklofenak farmakologie   MeSH
• Enterobacteriaceae účinky léků   metabolismus   MeSH
• fosfatidylethanolaminy chemie   metabolismus   MeSH
• fosfatidylglyceroly chemie   metabolismus   MeSH
• fosfolipidy chemie   metabolismus   MeSH
• lipidomika MeSH
• mastné kyseliny chemie   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH

There is an assortment of layered transition metal dichalcogenides (TMDs), about 40 reported compounds, each with its unique polymorph and properties. Group 4 TMD, titanium disulfide (TiS2), possess high electronic conductivity and light weight amongst other attractive features. In consideration for electrochemical and thermoelectrical applications, doping is a promising approach to enhance its practicability. The introduction of foreign atoms or compositional variance may improve existing properties or grant access to new ones. Moving away from the more intensively studied and successfully doped group 6 MoS2 and WS2, TiS2 is doped with varying levels of niobium (Nb) via controlled heating of stoichiometric amounts to yield Ti1-xNbxS2 where x = 0.05, 0.1, 0.2. Structural effects are discussed together with two doping parameters, nature and concentration of dopant. Characterisation data reveal retention of 1T-phase polymorph despite formation of TiS3 nanobelts upon doping. Fundamental electrochemical properties such as heterogenous electron transfer rates and its charge transfer resistance are compared amongst the materials of interest. A selective and sensitive 2nd generation electrochemical biosensor is prepared using Ti0.95Nb0.05S2/GOx/GTA since it is the most superior material in glucose detection.

• MeSH
• biosenzitivní techniky metody   MeSH
• elektrochemické techniky MeSH
• elektrody MeSH
• enzymy analýza   chemie   MeSH
• fosfatidylethanolaminy chemie   MeSH
• niob chemie   MeSH
• senzitivita a specificita MeSH
• spektrální analýza MeSH
• titan chemie   MeSH
• Publikační typ
• časopisecké články MeSH

The colloidal stability, in vitro toxicity, cell association, and in vivo pharmacokinetic behavior of liposomes decorated with monomethoxy-poly(ethylene glycol)-lipids (mPEG-lipids) with different chemical features were comparatively investigated. Structural differences of the mPEG-lipids used in the study included: (a) surface-anchoring moiety [1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE), cholesterol (Chol), and cholane (Chln)]; (b) mPEG molecular weight (2 kDa mPEG45 and 5 kDa mPEG114); and (c) mPEG shape (linear and branched PEG). In vitro results demonstrated that branched (mPEG114)2-DSPE confers the highest stealth properties to liposomes (∼31-fold lower cell association than naked liposomes) with respect to all PEGylating agents tested. However, the pharmacokinetic studies showed that the use of cholesterol as anchoring group yields PEGylated liposomes with longer permeance in the circulation and higher systemic bioavailability among the tested formulations. Liposomes decorated with mPEG114-Chol had 3.2- and ∼2.1-fold higher area under curve (AUC) than naked liposomes and branched (mPEG114)2-DSPE-coated liposomes, respectively, which reflects the high stability of this coating agent. By comparing the PEGylating agents with same size, namely, linear 5 kDa PEG derivatives, linear mPEG114-DSPE yielded coated liposomes with the best in vitro stealth performance. Nevertheless, the in vivo AUC of liposomes decorated with linear mPEG114-DSPE was lower than that obtained with liposomes decorated with linear mPEG114-Chol. Computational molecular dynamics modeling provided additional insights that complement the experimental results.

• MeSH
• biologická dostupnost MeSH
• cholany aplikace a dávkování   chemie   farmakokinetika   MeSH
• cholesterol aplikace a dávkování   chemie   farmakokinetika   MeSH
• fosfatidylethanolaminy aplikace a dávkování   chemie   farmakokinetika   MeSH
• HeLa buňky MeSH
• lidé MeSH
• lipidy MeSH
• liposomy MeSH
• molekulová hmotnost MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• nosiče léků farmakokinetika   MeSH
• polyethylenglykoly aplikace a dávkování   chemie   farmakokinetika   MeSH
• povrchové vlastnosti MeSH
• příprava léků metody   MeSH
• simulace molekulární dynamiky MeSH
• stabilita léku MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

A set of three psychrotrophic bacterial strains was isolated from different soil samples collected at the deglaciated northern part of James Ross Island (Antarctica) in 2014. All isolates were rod-shaped, Gram-stain-negative, non-motile, catalase-positive and oxidase-negative, and produced moderately slimy red-pink pigmented colonies on Reasoner's 2A (R2A) agar. A polyphasic taxonomic approach based on 16S rRNA gene sequencing, whole-genome sequencing, automated ribotyping, MALDI-TOF MS, chemotaxonomy methods and extensive biotyping using conventional tests and commercial identification kits was applied to the isolates in order to clarify their taxonomic position. Phylogenetic analysis based on the 16S rRNA gene showed that all isolates belonged to the genus Hymenobacter with the closest relative being Hymenobacter aerophilus DSM 13606T, exhibiting 98.5 % 16S rRNA gene pairwise similarity to the reference isolate P6312T. Average nucleotide identity values calculated from the whole-genome sequencing data proved that P6312T represents a distinct Hymenobacter species. The major components of the cellular fatty acid composition were summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), C16 : 1ω5c, summed feature 4 (C17 : 1 anteiso B/iso I), C15 : 0 anteiso and C15 : 0 iso. The menaquinone system of strain P6312T contained MK-7 as the major respiratory quinone. The predominant polar lipids were phosphatidylethanolamine and an unidentified phospholipid. Moderate to minor amounts of three unidentified polar lipids, four unidentified aminophospholipids, one unidentified glycolipid and one unidentified phospholipid were also present. Based on the obtained results, we propose a novel species for which the name Hymenobacterhumicola sp. nov. is suggested, with the type strain P6312T (=CCM 8763T=LMG 30612T).

• MeSH
• Cytophagaceae klasifikace   izolace a purifikace   MeSH
• DNA bakterií genetika   MeSH
• fosfatidylethanolaminy chemie   MeSH
• fosfolipidy chemie   MeSH
• fylogeneze * MeSH
• glykolipidy chemie   MeSH
• mastné kyseliny chemie   MeSH
• pigmentace MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• sekvenční analýza DNA MeSH
• techniky typizace bakterií MeSH
• vitamin K 2 analogy a deriváty   chemie   MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH

A group of rod-shaped, aerobic, Gram-stain-negative, gliding bacteria producing flexirubin-type pigment was isolated from environmental samples collected in Antarctica in 2009-2014. Phylogenetic analysis of the almost complete 16S rRNA gene sequences revealed two separated branches belonging to the genus Flavobacterium. Group I (n=8), represented by strain CCM 8826T, shared the highest sequence similarity to Flavobacterium collinsii 983-08T (98.8 %) and Flavobacterium saccharophilum DSM 1811T (98.4 %), and group II (n=4) represented by strain CCM 8827T shared the highest similarity to Flavobacterium aquidurense WB 1.1-56T (99.6 %). High genetic homogeneity of both groups, separation from each other and from phylogenetically close Flavobacterium species was verified by the rep-PCR fingerprinting method. DNA-DNA hybridization confirmed low genomic relatedness between strain CCM 8826T and F. collinsii 983-08T and F. saccharophilum DSM 1811T (18 and 28 %, respectively) and between strain CCM 8827T and F. aquidurense WB 1.1-56T (27 %). Chemotaxonomic analyses of strains CCM 8826T and CCM 8827T revealed the respiratory quinone to be MK-6, the major identified polar lipid was phosphatidylethanolamine and the predominant polyamine was sym-homospermidine. The common major fatty acids were C15 : 0 iso, C17 : 0 iso 3OH, C15 : 1 iso G, Summed Feature 3 (C16 : 1ω7c/C16 : 1ω6c), C15 : 0 iso 3OH and additionally, C15 : 0 anteiso among group II members. All analyses confirmed that strains of group I and II represent two novel species of the genus Flavobacterium, for which the names Flavobacterium chryseum sp. nov. (type strain CCM 8826T=P3160T=LMG 30615T) and Flavobacterium psychroterrae sp. nov. (type strain CCM 8827T=P3922T=LMG 30616T) are proposed.

• MeSH
• DNA bakterií genetika   MeSH
• Flavobacterium klasifikace   genetika   izolace a purifikace   MeSH
• fosfatidylethanolaminy chemie   MeSH
• fylogeneze * MeSH
• hybridizace nukleových kyselin MeSH
• mastné kyseliny chemie   MeSH
• pigmentace MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• sekvenční analýza DNA MeSH
• spermidin analogy a deriváty   chemie   MeSH
• techniky typizace bakterií MeSH
• vitamin K 2 analogy a deriváty   chemie   MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH

BACKGROUND AND PURPOSE: Endocannabinoids play an important role in modulating spinal nociceptive signalling, crucial for the development of pain. The cannabinoid CB1 receptor and the TRPV1 cation channel are both activated by the endocannabinoid anandamide, a product of biosynthesis from the endogenous lipid precursor N-arachidonoylphosphatidylethanolamine (20:4-NAPE). Here, we report CB1 receptor- and TRPV1-mediated effects of 20:4-NAPE on spinal synaptic transmission in control and inflammatory conditions. EXPERIMENTAL APPROACH: Spontaneous (sEPSCs) and dorsal root stimulation-evoked (eEPSCs) excitatory postsynaptic currents from superficial dorsal horn neurons in rat spinal cord slices were assessed. Peripheral inflammation was induced by carrageenan. Anandamide concentration was assessed by mass spectrometry. KEY RESULTS: Application of 20:4-NAPE increased anandamide concentration in vitro. 20:4-NAPE (20 μM) decreased sEPSCs frequency and eEPSCs amplitude in control and inflammatory conditions. The inhibitory effect of 20:4-NAPE was sensitive to CB1 receptor antagonist PF514273 (0.2 μM) in both conditions, but to the TRPV1 antagonist SB366791 (10 μM) only after inflammation. After inflammation, 20:4-NAPE increased sEPSCs frequency in the presence of PF514273 and this increase was blocked by SB366791. CONCLUSIONS AND IMPLICATIONS: While 20:4-NAPE treatment inhibited the excitatory synaptic transmission in both naive and inflammatory conditions, peripheral inflammation altered the underlying mechanisms. Our data indicate that 20:4-NAPE application induced mainly CB1 receptor-mediated inhibitory effects in naive animals while TRPV1-mediated mechanisms were also involved after inflammation. Increasing anandamide levels for analgesic purposes by applying substrate for its local synthesis may be more effective than systemic anandamide application or inhibition of its degradation. LINKED ARTICLES: This article is part of a themed section on Recent Advances in Targeting Ion Channels to Treat Chronic Pain. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.12/issuetoc.

• MeSH
• buňky zadních rohů míšních účinky léků   metabolismus   MeSH
• fosfatidylethanolaminy chemická syntéza   chemie   farmakologie   MeSH
• hmotnostní spektrometrie MeSH
• karagenan MeSH
• krysa rodu rattus MeSH
• mícha účinky léků   metabolismus   MeSH
• nervový přenos účinky léků   MeSH
• potkani Wistar MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zánět chemicky indukované   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

A bacterial strain designated CCM 8645T was isolated from a soil sample collected nearby a mummified seal carcass in the northern part of James Ross Island, Antarctica. The cells were short rods, Gram-stain-negative, non-motile, catalase and oxidase positive, and produced a red-pink pigment on R2A agar. A polyphasic taxonomic approach based on 16S rRNA gene sequencing, extensive biotyping using conventional tests and commercial identification kits and chemotaxonomic analyses were applied to clarify its taxonomic position. Phylogenetic analysis based on the 16S rRNA gene placed strain CCM 8645T in the genus Mucilaginibacter with the closest relative being Mucilaginibacter daejeonensis Jip 10T, exhibiting 96.5 % 16S rRNA pairwise similarity which was clearly below the 97 % threshold value recommended for species demarcation. The major components in fatty acid profiles were Summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), C15 : 0 iso and C17 : 0 iso 3OH. The cellular quinone content was exclusively menaquinone MK-7. The major polyamine was sym-homospermidine and predominant polar lipids were phosphatidylethanolamine and phosphatidylserine. Based on presented results, we propose a novel species for which the name Mucilaginibacter terrae sp. nov. is suggested, with the type strain CCM 8645T (=LMG 29437T).

• MeSH
• Bacteroidetes klasifikace   genetika   izolace a purifikace   MeSH
• DNA bakterií genetika   MeSH
• fosfatidylethanolaminy chemie   MeSH
• fosfatidylseriny chemie   MeSH
• fylogeneze * MeSH
• mastné kyseliny chemie   MeSH
• pigmentace MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• sekvenční analýza DNA MeSH
• spermidin analogy a deriváty   chemie   MeSH
• techniky typizace bakterií MeSH
• vitamin K 2 analogy a deriváty   chemie   MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH

The tear film is a thin multilayered structure covering the cornea. Its outermost layer is a lipid film underneath of which resides on an aqueous layer. This tear film lipid layer (TFLL) is itself a complex structure, formed by both polar and nonpolar lipids. It was recently suggested that due to tear film dynamics, TFLL contains inhomogeneities in the form of polar lipid aggregates. The aqueous phase of tear film contains lachrymal-origin proteins, whereby lysozyme is the most abundant. These proteins can alter TFLL properties, mainly by reducing its surface tension. However, a detailed nature of protein-lipid interactions in tear film is not known. We investigate the interactions of lysozyme with TFLL in molecular details by employing coarse-grained molecular dynamics simulations. We demonstrate that lysozyme, due to lateral restructuring of TFLL, is able to penetrate the tear lipid film embedded in inverse micellar aggregates.

• MeSH
• adsorpce MeSH
• estery cholesterolu chemie   MeSH
• fosfatidylcholiny chemie   MeSH
• fosfatidylethanolaminy chemie   MeSH
• kinetika MeSH
• lidé MeSH
• muramidasa chemie   MeSH
• povrchové napětí MeSH
• sfingomyeliny chemie   MeSH
• simulace molekulární dynamiky * MeSH
• slzy chemie   MeSH
• sulfoglykosfingolipidy chemie   MeSH
• termodynamika MeSH
• triolein chemie   MeSH
• voda chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Strain P4487AT was isolated during investigation of cultivable bacterial populations of environmental materials sampled at James Ross Island, Antarctica. It revealed Gram-stain-negative short rod-shaped cells producing a pink pigment. Phylogenetic analysis based on 16S rRNA gene sequences allocated strain P4487AT to the genus Pedobacter but showed that the strain represents a distinct intrageneric phylogenetic lineage clearly separated from remaining Pedobacter species. Phylogenetically, strain P4487AT formed a common branch with the Pedobacter arcticus and Pedobacter lignilitoris cluster while the highest value of 94.4 % 16S rRNA gene sequence similarity suggested that Pedobacter lentus is the most closely related species. Biochemical and physiological test results enabled the differentiation of strain P4487AT from all phylogenetically closely related species. Chemotaxonomic analyses of strain P4487AT showed MK-7 as the respiratory menaquinone, sym-homospermidine as the major polyamine, phosphatidylethanolamine and two unidentified lipids as the major polar lipids, presence of sphingolipids, and C16 : 1ω7c/C16 : 1ω6c (summed feature 3), iso-C15 : 0 and iso-C17 : 0 3-OH as the major fatty acids, all of which corresponded with characteristics of the genus Pedobacter. The results showed that strain P4487AT represents a novel species within the genus Pedobacter, for which the name Pedobacter psychrophilus sp. nov. is proposed. The type strain is P4487AT (=CCM 8644T=LMG 29436T).

• MeSH
• DNA bakterií genetika   MeSH
• fosfatidylethanolaminy chemie   MeSH
• fylogeneze * MeSH
• mastné kyseliny chemie   MeSH
• Pedobacter klasifikace   genetika   izolace a purifikace   MeSH
• pigmentace MeSH
• půdní mikrobiologie * MeSH
• RNA ribozomální 16S genetika   MeSH
• sekvenční analýza DNA MeSH
• sfingolipidy chemie   MeSH
• spermidin analogy a deriváty   chemie   MeSH
• techniky typizace bakterií MeSH
• vitamin K 2 analogy a deriváty   chemie   MeSH
• zastoupení bazí MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Antarktida MeSH