Investigating Membrane-Mediated Antimicrobial Peptide Interactions with Synchrotron Radiation Far-Infrared Spectroscopy

Synchrotron radiation-based Fourier transform infrared spectroscopy enables access to vibrational information from mid over far infrared to even terahertz domains. This information may prove critical for the elucidation of fundamental bio-molecular phenomena including folding-mediated innate host defence mechanisms. Antimicrobial peptides (AMPs) represent one of such phenomena. These are major effector molecules of the innate immune system, which favour attack on microbial membranes. AMPs recognise and bind to the membranes whereupon they assemble into pores or channels destabilising the membranes leading to cell death. However, specific molecular interactions responsible for antimicrobial activities have yet to be fully understood. Herein we probe such interactions by assessing molecular specific variations in the near-THz 400–40 cm⁻¹ range for defined helical AMP templates in reconstituted phospholipid membranes. In particular, we show that a temperature-dependent spectroscopic analysis, supported by 2D correlative tools, provides direct evidence for the membrane-induced and folding-mediated activity of AMPs. The far-FTIR study offers a direct and information-rich probe of membrane-related antimicrobial interactions.     

Local Structure Analysis and Modelling of Lignin-Based Carbon Composites through the Hierarchical Decomposition of the Radial Distribution Function

Carbonized lignin has been proposed as a sustainable and domestic source of activated, amorphous, graphitic, and nanostructured carbon for many industrial applications as the structure can be tuned through processing conditions. However, the inherent variability of lignin and its complex physicochemical structure resulting from feedstock and pulping selection make the Process-Structure-Property-Performance (PSPP) relationships hard to define. In this work, radial distribution functions (RDFs) from synchrotron X-ray and neutron scattering of lignin-based carbon composites (LBCCs) are investigated using the Hierarchical Decomposition of the Radial Distribution Function (HDRDF) modelling method to characterize the local atomic environment and develop quantitative PSPP relationships. PSPP relationships for LBCCs defined by this work include crystallite size dependence on lignin feedstock as well as increasing crystalline volume fraction, nanoscale composite density, and crystallite size with increasing reduction temperature.     

Synthesis and properties of cellulose nanocrystal conjugates with reactive dyes

Cellulose - In this work, we have developed methods of synthesis of cellulose nanocrystal (CNC) conjugates with chlorotriazine reactive dyes (RDs)—reactive violet, reactive-bright red and...     

Synthesis,structure, and properties of 2-[(4,6-di-tert-butyl-2,3-dihydroxyphenyl)thio]acetic acid amides

Russian Chemical Bulletin - New potential biologically active derivatives, in which the sterically hindered pyrocatechol moiety is linked through a 2-thioacetyl covalent bridge to a number of...     

Synthesis of functionalized tetrahydropyridones by the tandem Knoevenagel—Michael—intramolecular ammonolysis—alkylation reaction

Russian Chemical Bulletin - The tandem Knoevenagel—Michael—intramolecular ammonolysis—alkylation reaction was used to synthesize functionalized tetrahydropyridones. The molecular...     

Kinetic regularities of thermal decomposition of polycarbonate films containing Pt,Au, Ag,and Ni nanoparticles

Russian Chemical Bulletin - The kinetic regularities of thermal destruction of polycarbonate films containing Pt, Au, Ag, and Ni nanoparticles were studied. Scanning and transmission electron...     

Determination of Indicator Congeners of Polychlorinated Biphenyls in Water at Ultratrace Levels by Gas Chromatography–Tandem Mass Spectrometry

Journal of Analytical Chemistry - We validated a procedure for the determination of indicator congeners (ICs) of polychlorinated biphenyls (PCBs) (IUPAC nos. 28, 52, 101, 118, 138, 153, and 180) in...     

Stability of Highly Concentrated Water-in-Oil Emulsions with Magnetic Nanoparticles and the Structure of Highly Porous Polymers Formed on Their Basis

Colloid Journal - The influence of the concentration and size of magnetite nanoparticles on the stability of highly concentrated water-in-oil emulsions containing styrene–divinylbenzene...     

Synthesis and evaluation of the antioxidant properties for some novel aminomethyl derivatives of 2,6-diisobornylphenol bearing a pinane moiety

Some new derivatives based on 2,6-diisobornylphenol and containing amine moieties of the pinane structure at the para-position relative to the phenolic hydroxy group were synthesized. The antioxidant properties of the obtained compounds were estimated using various in vitro models. The introduction of diamine moiety into a starting molecule led to a significant increase in the radical scavenging activity and the ability to chelate Fe²⁺ ions.

     

Effect of MQ-copolymer and polymethylsilsesquioxane on thermal and mechanical properties of highly filled polyisoprene

Russian Chemical Bulletin - Highly filled vulcanizates based on polyisoprene, organosilicon fillers (polymethylsilsesquioxane and MQ-copolymers), and p-quinone dioxime derivative as a rubber...