Fluorescence of the Retinal Chromophore in Microbial and Animal Rhodopsins.

Fluorescence of the vast majority of natural opsin-based photoactive proteins is extremely low, in accordance with their functions that depend on efficient transduction of absorbed light energy. However, several recently proposed classes of engineered rhodopsins with enhanced fluorescence, along with the discovery of a new natural highly fluorescent rhodopsin, NeoR, opened a way to exploit these transmembrane proteins as fluorescent sensors and draw more attention to studies on this untypical rhodopsin property. Here, we review the available data on the fluorescence of the retinal chromophore in microbial and animal rhodopsins and their photocycle intermediates, as well as different isomers of the protonated retinal Schiff base in various solvents and the gas phase.

C adduct with L-arginine as a promising nanomaterial for treating cerebral ischemic stroke.

The work aimed to investigate the biocompatibility and biological activity of the water-soluble fullerene adduct C-Arg. It was found that the material is haemocompatible, is not cyto- and genotoxic, possesses pronounced antioxidant activity. Additionally, this paper outlines the direction of application of water-soluble fullerene adducts in the creation of neuroprotectors.

3D and Inkjet Printing by Colored Mie-Resonant Silicon Nanoparticles Produced by Laser Ablation in Liquid.

Optically resonant silicon nanoparticles have emerged as a prospective platform for the structural coloration of surfaces because of their strong and spectrally selective light scattering. In this work, we developed colorful inks based on polymer mixed with monodisperse Mie-resonant silicon nanoparticles for 3D and inkjet printing. We applied a laser ablation method in a flow cell for the mass production of silicon nanoparticles in water and separated the resulting nanoparticles with different sizes by density-gradient centrifugation.

Fluorescence Imaging of Cell Membrane Potential: From Relative Changes to Absolute Values.

Membrane potential is a fundamental property of biological cells. Changes in membrane potential characterize a vast number of vital biological processes, such as the activity of neurons and cardiomyocytes, tumorogenesis, cell-cycle progression, etc. A common strategy to record membrane potential changes that occur in the process of interest is to utilize organic dyes or genetically-encoded voltage indicators with voltage-dependent fluorescence.

Biocompatibility and biological activity of C fullerene adduct with L-threonine (C(CHNO)).

The aim of this work is to synthesise and study the biocompatibility and biological activity of the C fullerene adduct with l-threonine (C-Thr). The obtained adduct was identified using a complex of physicochemical methods, namely, C NMR spectroscopy, IR spectroscopy, thermogravimetric analysis, electron spectroscopy, elemental analysis, and high-performance liquid chromatography. The study of biocompatibility and biological activity of the C-Thr adduct included the study of haemocompatibility (haemolysis, platelet aggregation, plasma coagulation haemostasis, binding to human serum albumin, esterase activity), antiradical activity, cytotoxicity, cell proliferation, and interaction with DNA (determination of the DNA binding constant and genotoxicity).

Multicomponent Reactions Involving Diazo Reagents: A 5-Year Update.

This review summarizes recent developments in multicomponent reactions of diazo compounds. The role of diazo reagent and the type of interaction between components was analyzed to structure the discussion. In contrast to previous reviews on related topics mostly focused on metal catalyzed transformations, a substantial amount of organocatalytic or catalyst-free methodologies is covered in this work.

Bioimpedance Spectroscopy: Basics and Applications.

In this review, we aim to introduce the reader to the technique of electrical impedance spectroscopy (EIS) with a focus on its biological, biomaterials, and medical applications. We explain the theoretical and experimental aspects of the EIS with the details essential for biological studies, i.e.

Stretching force constants as descriptors of energy and geometry of F···HF hydrogen bonds.

In this work applicability of proton donor group stretching vibration force constants k and intermolecular stretching force constants k for evaluations of hydrogen bond strength and geometry are discussed. For a set of 30 complexes with F···HF hydrogen bonds in a wide range 0.5-48 kcal/mol by means of quantum chemical calculations equilibrium geometries, complexation energies, vibrational frequencies and corresponding force constants were calculated (MP2/aug-cc-pVTZ).

Quantum Mechanical and Molecular Mechanics Modeling of Membrane-Embedded Rhodopsins.

Computational chemistry provides versatile methods for studying the properties and functioning of biological systems at different levels of precision and at different time scales. The aim of this article is to review the computational methodologies that are applicable to rhodopsins as archetypes for photoactive membrane proteins that are of great importance both in nature and in modern technologies. For each class of computational techniques, from methods that use quantum mechanics for simulating rhodopsin photophysics to less-accurate coarse-grained methodologies used for long-scale protein dynamics, we consider possible applications and the main directions for improvement.

1,2,4-Oxadiazole/2-Imidazoline Hybrids: Multi-target-directed Compounds for the Treatment of Infectious Diseases and Cancer.

Replacement of amide moiety with the 1,2,4-oxadiazole core in the scaffold of recently reported efflux pump inhibitors afforded a novel series of oxadiazole/2-imidazoline hybrids. The latter compounds exhibited promising antibacterial activity on both Gram-positive (, ) and Gram-negative (, ) strains. Furthermore, selected compounds markedly inhibited the growth of certain drug-resistant bacteria.