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The novel classes of acylated phenoxyanilide and thiourea compounds were investigated for their ability to inhibit TEM type β-lactamase enzyme. Two compounds 4g and 5c reveal the ...inhibition potency in micromolar range and show their action by non-covalent binding in the vicinity of the TEM-171 active site. The structure activity relationship around carbon chain length and different substituents in ortho- and para-positions of acylated phenoxyanilide as well as molecular modelling study has been performed.
Production of extended-spectrum β-lactamases (ESBLs) is the one of most widespread and clinically significant mechanism of
Enterobacteriaceae resistance towards modern β-lactam antibiotics. There are ...known 400 ESBLs, with the majority represented by the enzymes of TEM, SHV and CTX-M families. Oligonucleotide microarrays with colorimetric detection have been developed for the purposes of determination of ESBLs and inhibitor-resistant β-lactamases using horseradish peroxidase (HRP). Specific oligonucleotide probes have been designed for the identification of β-lactamase family and important SNPs responsible for the broadening of substrate specificity and tolerance to inhibitors. Multiplex PCR has been developed for simultaneous amplification and labeling of full-size genes of TEM-, SHV- and CTX-M-type β-lactamases with biotin. The labeled target DNA is then hybridized with specific oligonucleotide probes immobilized on a porous membrane support. After hybridization, biotin-labeled DNA duplexes are stained with the streptavidin–HRP conjugate detected colorimetrically. Design of oligonucleotide probes and optimization of hybridization conditions ensure the specificity of all control ESBLs identification. The newly developed method has been successfully used to identify
bla
TEM,
bla
SHV and
bla
CTX-M genes in 90 clinical isolates of
Enterobacteriaceae: 70% were found to carry
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TEM, 50%
bla
SHV, 50%
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CTX-M; with the following distribution of CTX-M subclusters: 68%
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CTX-M-1, 4%
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CTX-M-2, and 14%
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CTX-M-9. No ESBL of TEM-type and IRT phenotype assigned to TEM- or SHV-type β-lactamases had been detected; 24.6% of clinical samples show two types of ESBLs simultaneously. A mixture of CTX-M-1-like and SHV-5-like genes was the most abundant combination detected. Membrane microarray technique with colorimetric detection provides both high specificity and effectiveness of screening for ESBL- and IRT-producing samples.
The general approach for site-oriented immobilization of antibodies onto gold supports is reported. The immobilization is carried out using the native sulfide groups of immunoglobulin (IgG). To ...liberate the thiol groups, the intact IgG was split into two half-IgG fragments without destruction of the binding site of the antibody. The immobilization of half-IgG fragments on the gold surface was carried out by simple adsorption. The antigen binding capacity of the half-IgG modified gold supports is similar to that of the gold surfaces with the traditionally linked antibodies and is much higher than for nonspecifically adsorbed intact IgGs. The immobilized antibodies, according to the proposed approach, maintain high antigen binding constants. The immobilization procedure provides orientation of IgG fragments in terms of the similar distance between the binding site of the antibody and the surface of the gold support, which does not cause the distribution of the apparent affinity constants. The high operational stability of half-IgG modified gold electrodes makes them applicable for analytical applications.
Organic and hybrid molecular systems Ananikov, Valentine P.; Khokhlova, Elena A.; Egorov, Mikhail P. ...
Mendeleev communications,
March-April 2015, 2015-03-00, Letnik:
25, Številka:
2
Journal Article
Recenzirano
The design of functional organic and hybrid molecular systems has shown outstanding recent growth and is a high priority in the development of new technologies and novel functional materials. Recent ...advancements in the chemical sciences have provided fascinating opportunities to access the most complex molecular architectures ever possible so far. Herein, we discuss the principles of the structural organization of recently studied molecular systems, basic approaches for their assembly, and challenging directions for their practical applications.
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The rapid development of organic chemistry and catalysis has provided outstanding chemical tools to build complex molecular architectures that were never possible before. In spite of ...amazing progress in studying individual molecules and reactions, practical applications are limited due to the high cost of newly developed technologies and the difficulty in understanding the processes at the molecular level. Herein, we summarize our first steps and experiences carrying out an ongoing project on organic and hybrid molecular systems that highlights new fascinating opportunities and identifies future challenges.
Organic and hybrid systems: from science to practice Ananikov, Valentine P.; Eremin, Dmitry B.; Yakukhnov, Sergey A. ...
Mendeleev communications,
September-October 2017, 2017-09-00, Letnik:
27, Številka:
5
Journal Article
Recenzirano
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Organic systems still dominate several traditional areas of chemical science and well-known applications, such as the synthesis of pharmaceutical compounds and drugs. However, a ...fascinating trend has appeared recently to combine pure organic systems into advanced molecular architectures and to create hybrid molecular systems. These interdisciplinary areas, where possible connections between organic and hybrid systems may be developed, are the focus of the present review to develop valuable practical applications.
The temperature dependencies of photoluminescence efficiency of InGaAlAs/InGaAs/InP heterostructures with 1550 nm range strained quantum wells have been studied. The heterostructures had nine ...In0.74Ga0.26As quantum wells which were separated by In0.53Al0.20Ga0.27As barriers. The barriers were δ-doped with n- and p-type dopants with different layer concentrations of charge carriers. The both p-type and n-type doping of barriers leads to slight increase in the efficiency when doping level not exceeding values of (1–5)·1012 cm−2. Moreover, doping with an n-type dopant leads to a significant increase in the width of the photoluminescence spectrum, while doping with a p-type dopant leads to a decrease in its width, compared to a heterostructure with undoped barrier layers.
•The semiconductor heterostructures with strained InGaAs QWs were grown on semi-insulated InP (100) substrates using MBE.•The barriers were δ-doped with n - and p-type dopants with different layer concentrations of charge carriers.•The moderate doping of the barrier layers increases the efficiency of radiative recombination at low excitation levels.•N-doping of QWs barriers increases in the FWHM of PL spectra, while p-doping decreases FWHM, compared to a undoped barriers.•Obtained results can be used in the development of light-emitting structures for 1550 nm spectral range.
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