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N‐carbamoyl‐β‐alanine amidohydrolase (CβAA) constitutes one of the most important groups of industrially relevant enzymes used in the production of optically pure amino acids and derivatives. In this study, a CβAA‐encoding gene from Rhizobium radiobacter strain MDC 8606 was cloned and overexpressed in Escherichia coli. The purified recombinant enzyme (RrCβAA) showed a specific activity of 14 U·mg−1 using N‐carbamoyl‐β‐alanine as a substrate with an optimum activity at 55 °C and pH 8.0. In this work, we report also the first prokaryotic CβAA structure at a resolution of 2.0 Å. A discontinuous catalytic domain and a dimerisation domain attached through a flexible hinge region at the domain interface have been revealed. We identify key ligand binding residues, including a conserved glutamic acid (Glu131), histidine (H385) and arginine (Arg291). Our results allowed us to explain the preference of the enzyme for linear carbamoyl substrates, as large and branched carbamoyl substrates cannot fit in the active site of the enzyme. This work envisages the use of RrCβAA from R. radiobacter MDC 8606 for the industrial production of L‐α‐, L‐β‐ and L‐γ‐amino acids. The structural analysis provides new insights on enzyme–substrate interaction, which shed light on engineering of CβAAs for high catalytic activity and broad substrate specificity. [ABSTRACT FROM AUTHOR]

Nowadays, amino acids (AAs) and peptides with bulky side chains hold significant interest for organic synthesis and the modern pharma industry. Non-proteinogenic (or unnatural) AAs are key building blocks used for obtaining pharmaceutically relevant peptides and for the development of chiral molecular catalysts, and they are extensively used in the total synthesis of complex natural compounds. Thus, an elaboration of cost-effective methods for the preparation of novel unnatural AAs to increase their structural diversity is highly desirable. In this context, herein, we present an asymmetric metal-templated synthesis of a number of enantiomerically pure (S)-2-amino-2-methyl-5-arylpent-4-ynoic acids starting from commercially available reagents and Belokon's chiral auxiliary (S)-BPB, namely (S)-2-(N-benzylprolyl)aminobenzophenone. The construction of a chiral Ni(II) complex from alanine (Ala) and the subsequent propargylation, arylation by the Sonogashira cross-coupling reaction using various aryl halides, and, finally, an acidic decomposition of the obtained complexes deliver to the target complex α,α-disubstituted AAs featuring a triple bond in a side chain. Next, the Fmoc-protected α-AAs and dipeptide were synthesized. Finally, we examined the obtained α-AAs and peptide as collagenase inhibitors. [ABSTRACT FROM AUTHOR]

The article analyzes the issues of the legitimacy of war, the relationship between war and morality in the context of different ethical concepts. It is shown that the somewhat 'fashionable' notion of the ethics of war is actually problematic and does not clearly express the peculiarities of the relationship between war and morality. Analyzing the main conceptual discourses about war, it is argued that in some of them the acceptance of the legitimacy of war does not make sense with the logic of the watershed between war and morality. Analyzing the 44-day War separately for the first time in the context of the principles of the conception of just wars, it is argued that Azerbaijan's military aggression against Artsakh was actually accompanied by a gross violation of many of these principles, despite the propaganda efforts of the Azerbaijani side to claim the opposite. [ABSTRACT FROM AUTHOR]

Currently non-proteinogenic amino acids and synthetic peptides are widely used as building blocks in the drugs design. Many of these compounds are enzyme inhibitors or antimicrobials. Secreted Clostridium histolyticum collagenase is considered as a virulence factor and thus is an attractive target for fighting microbial infection. Trypsin is a target for the treatment of digestive disorders. This study was aimed to find new inhibitors of collagenase and trypsin. The interaction of non-proteinogenic amino acids and peptides with C. histolyticum collagenase and trypsin has been evaluated by Molecular Docking followed by the measurement of enzyme inhibition by selected compounds. According to the Docking analysis, N-tert-butoxycarbonylglycyl-(S)-2-amino-3-(4-((4-fluorophenyl)-ethynyl)-phenyl)-α-alanine has to demonstrate the most effective interaction with collagenase. Thus, the synthesis of this dipeptide was carried out. Measurement of enzymes activity revealed that both the dipeptide and the amino acid included in its structure inhibit collagenase and trypsin. The amino acid inhibited collagenase with IC50 = 0.32 mM and trypsin with IC50 = 0.57 mM. The dipeptide inhibited collagenase with IC50 = 0.62 mM and trypsin with IC50 = 89 uM. Keywords: bacterial collagenase, molecular docking, inhibitor, peptide synthesis. [ABSTRACT FROM AUTHOR]

Ni(II) complex of the Schiff base of the chiral auxiliary (S)-2- N -(N ′-benzylprolyl)aminobenzophenone (BPB) and dehydroalanine as the initial complex in the addition reaction was investigated. The obtained four new derivatives of α-alanine were investigated as inhibitors of aldose reductase. Only one of them: (S)-2-amino-3-[(4-methylbenzyl)amino]propanoic acid showed activity. It becomes a reason for studying the patterns of biological activity of the structure of α-amino acids. The results of docking analysis indicated that (S)-2-amino-3-[(4-methylbenzyl)amino]propanoic acid demonstrated the ability to form bonds with different functional groups of the enzyme which let us assume that some amino acids of nonfunctional groups, such as Trp20 of ALR2, can play a key role in inhibitor–enzyme interactions. [ABSTRACT FROM AUTHOR]

It is demonstrated that the use of a micrometric thin 39K vapor cell (MTC) and saturated absorption (SA) spectroscopy allows the formation of narrow atomic lines in the transmission spectrum without unwanted cross-over resonances. Another important feature is the small characteristic magnetic field value B 0 = A h f / μ B of 39K, significantly smaller than for Rb and Cs. As a consequence, decoupling of J and I can be observed at relatively low magnetic fields ∼300 G, which results in the formation of two groups of four spectrally-resolved and equidistantly-positioned atomic transitions having the same amplitude (each group corresponds to a given circular polarization σ ± ) which we record using a simple experimental setup with a linearly polarized tunable diode-laser and a longitudinal magnetic field obtained with two permanent magnets. Fabrication of a MTC is much easier than the fabrication of the 39K nanocells used in our previous works. A simple method to determine the magnitude of a wide range of B -fields with a spatial resolution of 30  µ m is presented, which is intrinsically calibrated and does not require a frequency reference. [ABSTRACT FROM AUTHOR]

Ni(II) complexes of the Schiff base of the chiral auxiliary (S)-2-N-(N′-benzylprolyl)aminobenzophenone (BPB) and α-substituted propargylglycines as the initial complexes in the Glaser reaction were investigated. Three new bis-derivatives of propargylglycine were obtained with high chemical yields. To study the patterns of biological activity of the structure of bis-derivatives of propargylglycine, mono analogs of these amino acids were obtained. Bis-derivative of propargylglycine selectively inhibited ALR2 while did not inhibit ALR1. Thus, (2S,9S)-2,9-diamino-2,9-bis(2-chlorobenzyl)deca-4,6-diynedioic selectively inhibited ALR2 with IC50 = 0.335 mM, while (S)-2-(2-chlorobenzyl)-2-aminopent-4-ynoic and (2S,9S)-2,9-diamino-2,9-bis(3-fluorobenzyl)deca-4,6-diynedioic acids showed inhibitory effect on ALR1 with IC50 = 0.49 mM and IC50 = 0.289 mM, respectively. The results of docking analysis indicated that both amino acids demonstrated the ability to form bonds with different functional groups of the enzyme. We assume that some amino acids of nonfunctional groups, such as Trp20 of ALR2, can play a key role in inhibitor–enzyme interactions. [ABSTRACT FROM AUTHOR]

In this paper we show that the second derivative (SD) technique of the absorption spectra of Rb atomic vapours, confined in a nanocell with a thickness ℓ = λ/2 = 398 nm, allows us to achieve close to Doppler-free spectroscopy. The narrow linewidth and linearity of the SD signal response with respect to transition probabilities allows us to study separately, in an external transverse magnetic field (0.6 to 4 kG), a large number of the atomic transitions of 85Rb and 87Rb atoms. Atomic transitions |Fg, 0⟩ → |Fe = Fg, 0′⟩, for which the dipole moment is null in a zero magnetic field (so-called magnetically-induced transitions), show a gigantic increase in probability with an increasing magnetic field. When a magnetic field is applied to the vapour, we show the possibility of forming a dark resonance on these transitions by adding a coupling laser. We are therefore able to demonstrate a five-fold increase in the transmission of the probe radiation when the coupling laser is on. Theoretical calculations are in very good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

The α-amylase producing strain was identified as Bacillus amyloliquefaciens by 16S rDNA phylogenetic analysis. After four stages of purification the enzyme isolated from culture supernatant of Bacillus amyloliquefaciens MDC1974 strain had more than 95 % purity with 557 U/mg specific activity. The purified enzyme showed 55 kDa molecular weight by SDS-PAG electrophoresis and 5.0 pI by isoelectric focusing. The optimal pH and temperature for enzyme activity were 6.5-7.0 and 60 °C, respectively. The enzyme was stable at pH range of 6.5-8.0 and temperature range of 45-60 °C. Purified enzyme did not adsorb neither potato, nor corn raw starches, but hydrolyzed both of them. The corn starch was preferable substrate for enzyme. The enzyme hydrolyzed 1 % (w/v) raw or gelatinized corn starch significantly during 24 h. At the beginning of hydrolyzes reaction the oligosaccharides were the main products. After long periods of hydrolysis, the yield of glucose and maltose were predominant. [ABSTRACT FROM AUTHOR]

Gordoniae are one of the most promising hydrocarbon‐oxidizing actinobacteria. Here we present the genome sequence analysis of thermotolerant strain Gordonia sp. 1D isolated from oil‐refinery soil. It is capable of alkane consumption and biosurfactant production at temperatures of up to 50°C. Gordonia sp. 1D demonstrates maximum biosurfactant production when grown on hexadecane, and at 40°C it was slightly higher than at 27°C: 35 and 39 mN/m, respectively. For the first time, it was experimentally confirmed that the carbohydrate component of extracellular biosurfactants produced by strain 1D is trehalose. In addition, genes for the production of trehalose lipid biosurfactants were identified. The genetic determinants for two different pathways for trehalose synthesis were found. The strain carries genes otsA and otsB involved in de novo trehalose biosynthesis. Moreover, the genes treY and treZ responsible for trehalose biosynthesis from maltooligosaccharides and starch or glycogen were identified. [ABSTRACT FROM AUTHOR]

Summary: Objective: Prolonged electroencephalographic (EEG) monitoring in chronic epilepsy rodent models has become an important tool in preclinical drug development of new therapies, in particular those for antiepileptogenesis, disease modification, and treating drug‐resistant epilepsy. We have developed an easy‐to‐use, reliable, computational tool for automated detection of electrographic seizures from prolonged EEG recordings in rodent models of epilepsy. Methods: We applied a novel method based on advanced time‐frequency analysis that detects EEG episodes with excessive activity in certain frequency bands. The method uses an innovative technique of short‐term spectral analysis, the Similar Basis Function algorithm. The method was applied for offline seizure detection from long‐term EEG recordings from four spontaneously seizing, chronic epilepsy rat models: the fluid percussion injury (n = 5 rats, n = 49 seizures) and post–status epilepticus models (n = 119 rats, n = 993 seizures) of acquired epilepsy, and two genetic models of absence epilepsy, Genetic Absence Epilepsy Rats from Strasbourg and Wistar Albino Glaxo from Rijswijk (n = 41 and 14 rats, n = 8733 and 825 seizures, respectively). Results: Our comparative analysis revealed that the EEG amplitude spectra of these four rat models are remarkably similar during epileptiform activity and have a single expressed peak within the 17‐ to 25‐Hz frequency range. Focusing on this band, our computer program detected all seizures in the 179 rats. A quick semiautomated user inspection of the EEGs for the period of each identified event allowed quick rejection of artifact events. The overall processing time for 12‐day‐long recordings varied from a few minutes (5‐10) to 30 minutes, depending on the number of artifact events, which was strongly correlated with the signal quality of the raw EEG data. Significance: Our automated seizure detection tool provides high sensitivity, with acceptable specificity, for long‐ and short‐term EEG recordings from both acquired and genetic chronic epilepsy rat models. This tool has the potential to improve the efficiency and rigor of preclinical research and therapy development using these models. [ABSTRACT FROM AUTHOR]

We show that the Faraday rotation (FR) in strong longitudinal magnetic fields is a convenient tool to study atomic transitions by using the line in a Cs vapour confined in a nanocell of thickness  nm. We use strong magnetic fields ranging from 0.1 to 6 kG, in which Cs atomic transitions are split into a large number of components, and FR signals of spectral width of ∼ 50 MHz are frequency-resolved allowing the investigation of individual transitions. For magnetic fields of several kG, the hyperfine Paschen-Back regime is reached that is manifested by the presence in the spectrum of the eight FR components having the amplitudes of the same height and located with almost equidistant frequencies. A remarkable feature of FR spectrum is the proportionality of its amplitude to the probability of an atomic transition in a strong magnetic field. A theoretical model which agrees well with the experiment is developed. [ABSTRACT FROM AUTHOR]

Magnetic field-induced giant modification of the probabilities of five transitions of 5 S , F = 2 → 5 P , F = 4 of Rb and three transitions of 5 S , F = 1 → 5 P , F = 3 of Rb forbidden by selection rules for zero magnetic field has been observed experimentally and described theoretically for the first time. For the case of excitation with circularly-polarized ( σ ) laser radiation, the probability of F = 2, m = − 2 → F = 4, m = − 1 transition becomes the largest among the seventeen transitions of Rb F = 2 → F = 1,2,3,4 group, and the probability of F = 1, m = − 1 → F = 3, m = 0 transition becomes the largest among the nine transitions of Rb F = 1 → F = 0,1,2,3 group, in a wide range of magnetic field 200-1000 G. Complete frequency separation of individual Zeeman components was obtained by implementation of derivative selective reflection technique with a 300 nm-thick nanocell filled with Rb, allowing formation of narrow optical resonances. Possible applications are addressed. The theoretical model is well consistent with the experimental results. Graphical abstract: [ABSTRACT FROM AUTHOR]

The electromagnetically induced transparency (EIT) phenomenon is studied using a nanometric thin (L = 795 nm) Rb vapour layer. EIT-type resonances that are formed in three different energy-level systems are reported. It is demonstrated that the EIT resonance which is formed in a Λ-system where the ground levels are separated by the hyperfine splitting (EITH-resonance) has the smallest linewidth (~10 MHz). The EIT resonance which is realized in a Λ-system formed by the Zeeman sublevels of theFg = 2 →Fe = 1 transition (EITZ-resonance) has a larger linewidth (~14 MHz). The EITV-resonance which is formed in the V-system has the largest linewidth (~40 MHz). The uniqueness of the EIT phenomena reported here is that they can be formed in different types of Λ-systems even forL < 1 μm. The splitting of the EITZ-resonance into two components in a transverse magnetic field is reported. The theoretical model well describes the experiment. [ABSTRACT FROM PUBLISHER]

Electromagnetically induced transparency (EIT) effect in a-system formed by Cs atomsline, enclosed in nanometric-thin cells, is studied both experimentally and theoretically for the first time. The atomic column thicknessvaries in the range of 50–1500 nm. It is demonstrated that when the coupling laser frequency is in exact resonance with the corresponding atomic transition, the parameters of the EIT resonance (also called dark resonance (DR)) depend weakly on, which allows us to detect DR at nm with the contrast of. The obtained DR parameters are the best as compared with those for Rbandlines and Csline. The DR contrast and width are studied versus laser frequency detunings, coupling laser power, cell thickness, temperature, and applied external magnetic field. The well-resolved splitting of the DR resonance in a magnetic field for nm can be used for magnetometry with high spatial resolution. The theoretical model describes well the observed results. [ABSTRACT FROM AUTHOR]

Electromagnetically induced transparency (EIT) resonances using the 5S1/2 → 5P3/2 → 5D5/2 ladder-system in optically thick Rb atomic vapour are studied. We observe a strong line narrowing effect and gain at the 5S1/2 → 5P3/2 transition wavelength due to an energy-pooling assisted frequency conversion with characteristics similar to 4-wave mixing. As a result it is possible to observe tunable and switchable transparency resonances with amplitude close to 100% and a linewidth of 15 MHz. In addition, the large line narrowing effect allows resolution of 85Rb 5D5/2 hyperfine structure even in the presence of strong power broadening. [ABSTRACT FROM AUTHOR]

The sub-natural width N-type resonance in a Λ-system, on the D2 line of Cs atoms is studied for the first time in the presence of a buffer gas (neon) and the radiations of two continuous narrow-band diode lasers. A L = 1 cm long cell is used to investigate the N-type process. The N-type resonance in a magnetic field for 133Cs atoms is shown to split into seven or eight components, depending on the magnetic field and laser radiation directions. The results obtained indicate that the levels Fg = 3, 4 are the initial and final ones in the N-resonance formation. The experimental results with magnetic field agree well with theoretical descriptions. [ABSTRACT FROM AUTHOR]

The two technical points below are corrected by this erratum: [ABSTRACT FROM AUTHOR]