Anna V. El'skaya

National Academy of Sciences of Ukraine | ISP · Department of Translation Mechanisms of Genetic Information

The combination of the generic mobile technology and inherent stability, versatility and cost-effectiveness of the synthetic receptors allows producing optical sensors for potentially any analyte of interest, and, therefore, to qualify as a platform technology for a fast routine analysis of a large number of contaminated samples. To support this st...

A novel smartphone-based optical biomimetic sensor based on free-standing molecularly imprinted polymer (MIP) membranes was developed for rapid and sensitive point-of-care detection of aflatoxin B1. The developed MIP membranes were capable of selective recognition of the target analyte and, at the same time, of generation of a fluorimetric sensor r...

Translation elongation factor 1Bβ (eEF1Bβ) is a metazoan-specific protein involved into the macromolecular eEF1B complex, containing also eEF1Bα and eEF1Bγ subunits. Both eEF1Bα and eEF1Bβ ensure the guanine nucleotide exchange on eEF1A while eEF1Bγ is thought to have a structural role. The structures of the eEF1Bβ catalytic C-terminal domain and n...

An excess of the excitatory neurotransmitter, glutamate, in the synaptic cleft during hypoxia/ischemia provokes development of neurotoxicity and originates from the reversal of Na⁺-dependent glutamate transporters located in the plasma membrane of presynaptic brain nerve terminals. Here, we have optimized an electrochemical glutamate biosensor usin...

The question of what governs the translation elongation rate in eukaryotes has not yet been completely answered. Earlier, different availability of different tRNAs was considered as a main factor involved, however, recent data revealed that the elongation rate does not always depend on tRNA availability. Here, we offer another, codon-independent ap...

Nanostructured polymeric membranes for selective recognition of aflatoxin B1 were synthesized in situ and used as highly sensitive recognition elements in the developed fluorescent sensor. Artificial binding sites capable of selective recognition of aflatoxin B1 were formed in the structure of the polymeric membranes using the method of molecular i...

An experimental approach for improving the sensitivity of the surface plasmon resonance (SPR) DNA hybridization sensor using gold nanoparticles (GNPs), modified by specific oligonucleotides, was elaborated. An influence of the ionic strength on the aggregation stability of unmodified GNPs and GNPs modified by the thiolated oligonucleotides was inve...

The research is aimed at the development and optimization of conductometric biosensor for determination of the inhibitory potency of patulin and verification of its feasibility after reactivation. A differential pair of gold interdigitated electrodes deposited on the sital substrate was used as the conductometric transducer of a signal. Urease, co-...

Development of a conductometric biosensor for the urea detection has been reported. It was created using a non-typical method of the recombinant urease immobilization via adsorption on nanoporous particles of silicalite. It should be noted that this biosensor has a number of advantages, such as simple and fast performance, the absence of toxic comp...

Translation elongation factor 1Bβ (eEF1Bβ) is a metazoan-specific protein catalyzing the guanine nucleotide exchange on translation elongation factor 1A (eEF1A). eEF1Bβ was reported to form oligomers. Aim: To define the structural region of human eEF1Bβ that mediates its self-association. In addition, the various truncated forms of this protein wer...

The eukaryotic translation elongation factor 1Bα (eEF1Bα) is a functional homologue of the bacterial factor EF-Ts and is a component of the macromolecular eEF1B complex. eEF1Bα functions as a catalyst of guanine nucleotide exchange in the translation elongation factor 1A (eEF1A). The C-terminal domain of eEF1Bα is necessary and sufficient for its c...

Mammalian translation elongation factor eEF1A is involved in ribosomal polypeptide synthesis. Also, the protein fulfills many additional duties in an eukaryotic cell. Here, we identified a novel partner of the eEF1A1 isoform, namely Sgt1, a protein that possesses co-chaperon properties and participates in antiviral defense processes. By applying di...

An interaction of the boron clusters closo-borates K2[B10H10], K2[B12H12] and their functionalized derivatives with serum proteins human (HSA) and bovine (BSA) albumins and immonoglobulin IgG as well as globular proteins β-lactoglobulin and lysozyme was characterized. The steady state and time resolved protein fluorescence quenching studies point o...

Translation elongation factor eEF1A is a G-protein which has a crucial role in the ribosomal polypeptide elongation and possesses a number of non-translational functions. Here, we show that the A,A∗,A' helices segment of mammalian eEF1A is dispensable for the eEF1A∗eEF1Bα complex formation. The A,A∗,A' helices region did not interact with actin; ho...

Eukaryotic elongation factor eEF1A transits between the GTP- and GDP-bound conformations during the ribosomal polypeptide chain elongation. eEF1A*GTP establishes a complex with the aminoacyl-tRNA in the A site of the 80S ribosome. Correct codon–anticodon recognition triggers GTP hydrolysis, with subsequent dissociation of eEF1A*GDP from the ribosom...

Aim. Optimization of a new method of enzyme immobilization for amperometric biosensor creation. Methods. The amperometric biosensor with glucose oxidase immobilized on zeolites as bioselective elements and platinum disk electrode as transducers of biochemical signal into the electric one was used in the work. Results. The biosensors based on glucos...

Aim. Development of an easy-to-use colorimetric sensor system for fast and accurate detection of phenol in environmental samples. Methods. Technique of molecular imprinting, method of in situ polymerization of molecularly imprinted polymer membranes. Results. The proposed sensor is based on free-standing molecularly imprinted polymer (MIP) membrane...

Aim. To gain more insights into properties of the human translation elongation factor eEF1Bg and its interaction with partners we intended to produce the full-length protein and its truncated forms. Methods. cDNAs encoding truncated forms of eEF1Bg were generated by PCR amplification with respective primers and cloned into vectors providing polyhis...

Aim. To gain more insights into properties of the human translation elongation factor eEF1Bγ and its interaction with partners we intended to produce the full-length protein and its truncated forms. Methods. cDNAs encoding truncated forms of eEF1Bγ were generated by PCR amplification with respective primers and cloned into vectors providing polyhis...

Aim. To gain more insights into properties of the human translation elongation factor eEF1Bγ and its interaction with partners we intended to produce the full-length protein and its truncated forms.Methods. cDNAs encoding truncated forms of eEF1Bγ were generated by PCR amplification with respective primers and cloned into vectors providing polyhist...

Eukaryotic translation elongation factor 1A (eEF1A) exists as two 98 % homologous isoforms eEF1A1 and eEF1A2 that are tissue/development specific and differentially linked to apoptosis/cancerogenesis. A2 is over- expressed in a number of tumors while unusual expression of A1 is observed in injured muscles. To approach a possible mechanism underlyin...

Translation elongation factor 1A (eEF1A) directs aminoacyl-tRNA to the A site of 80S ribosome. In addition, more than 97% homologous variants of eEF1A, A1 and A2, whose expression in different tissues is mutually exclusive, may fulfill a number of independent moonlighting functions in cell, for instance, unusual appearance of A2 in an A1-expressing...

Background: Eukaryotic translation elongation factor 1A2 (eEF1A2) is a known proto-oncogene. We proposed that stimulation of the eEF1A2 expression in cancer tissues is caused by the loss of miRNA-mediated control. Methods: Impact of miRNAs on eEF1A2 at the mRNA and protein levels was examined by qPCR and western blot, respectively. Dual-luciferase...

The paper is a review of the researches of Biomolecular Electronics Laboratory concerning the development of biosensors based on electrochemical transducers (amperometric and conductometric electrodes, potentiometric pH-sensitive field effect transistors) and different biorecognition molecules (enzymes, cells, antibodies), biomimics (molecularly im...

Over 40 years of studies in the field of higher eukaryotic translation are summarized in the review. Among the pioneer results obtained we should especially accentuate the following: i) discovery of the adaptation of tRNAs and aminoacyl-tRNA synthetases (ARSs) cellular pools to the synthesis of specific proteins and modulation of the elongation rat...

An easy-to-use colorimetric test-system for the efficient detection of creatinine in aqueous samples was developed. The test-system is based on composite molecularly imprinted polymer (MIP) membranes with artificial receptor sites capable of creatinine recognition. A thin MIP layer was created on the surface of microfiltration polyvinylidene fluori...

Eukaryotic translation elongation factor 1A exists as two 98 % homologous isoforms: eEF1A1 (A1) and eEF1A2 (A2) which are tissue and development specific. Despite high homology in an open reading frame (ORF) region, mRNAs coding for eEF1A1 and eEF1A2 are different in their untranslated regions (UTR), suggesting a possibility of their dissimilar pos...

During postnatal development, the switch of the expression from isoform A1 to the isoform A2 of eukaryotic translation elongation factor (eEF1A) is observed in neuronal and muscle tissues. The switch of the expression is a vital fundamental process, as mutant mice, with the partial EEF1A2 deletion dies on the 28th day after birth. Mechanism of the...

Aim. The prostate tumor-inducing oncogene (PTI-1), presumably encoding a truncated form of eukaryotic translation elongation factor 1A1 (eEF1A1), was discovered as a gene overexpressed in prostate tumor samples and absent in normal tissues. The mechanism of PTI-1 oncogenicity remains obscure. Methods. Several bioinformatics methods were applied to...

The highly sensitive and selective potentiometric biosensor for creatinine determination has been developed by us earlier. In it, pH-sensitive field effect transistors were used as transducer and immobilized creatinine deiminase (EC 3.5.4.21)--as a biosensitive element. In the work presented, we optimized this biosensor for creatinine analysis in r...

Translation elongation factor eEF1A2 was purified to homogeneity from rabbit muscle by two consecutive ion-exchange column-chromatography steps and this mammalian eEF1A2 was successfully crystallized for the first time. Protein crystals obtained using ammonium sulfate as precipitant diffracted to 2.5 Å resolution and belonged to space group P6 122...

Phosphoproteomics is often aimed at deciphering the modified components of signaling pathways in certain organisms, tissues and pathologies. Phosphorylation of housekeeping proteins, albeit important, usually attracts less attention. Here, we provide targeted analysis of eukaryotic translation elongation factor 1A (eEF1A), which is the main element...

A differential pair of planar thin-film interdigitated electrodes, deposited on a ceramic pad, was used as a conductometric transducer. The three-enzyme system (invertase, mutarotase, glucose oxidase), immobilized on the transducer surface, was used as a bioselective element. The ratio between enzymes in the membrane was found experimentally consid...

Aim. To investigate the expression of all eEF1 complex subunits at the mRNA and protein levels in human renal cancer. Methods. The protein content and mRNA level of the eEF1 complex components were analyzed in 18 clinical human renal carcinoma specimens and correspondingly paired normal tissues by Western blot and Northern blot techniques. Results....

The signalling role of individual subunits released from some stable translation multi-molecular complexes under unfavourable circumstances is known. The disease-related role of the translation elongation factor 1 complex (eEF1) as a whole is never researched; however, its subunits possess apparent regulatory potency. Whether the individual eEF1 su...

Aim. To investigate protein level of all subunits of the eukaryotic elongation translation factor eEF1H (eEF1A, eEF1Bα, eEF1Bβand eEF1Bγ) in glial tumors of human brain in comparison with normal brain. Methods. The eEF1H components content has been investigated in human glioblastoma clinical samples by Western blot analysis. Results. To determine t...

The work is aimed at confirmation of earlier assumed mechanism of tRNA channeling. Methods. The methods of band shift assay and Forsters resonance energy transfer were used. Results. The affinities of mammalian tRNAs for two tissue specific isoforms of elongator factor eEF1A1 and eEF1A2 were compared. For the first time we have shown the ability of...

Aim. The analysis of toxicity of different water samples with the multibiosensor developed earlier. Methods. The potentiometric multibiosensor with several immobilized enzymes as bioselective elements and the matrix of pH-sensitive field effect transistors as transducers of the biochemical signal into the electric one was applied for the analysis....

COTRASIF is a web-based tool for the genome-wide search of evolutionary conserved regulatory regions (transcription factor-binding sites, TFBS) in eukaryotic gene promoters. Predictions are made using either a position-weight matrix search method, or a hidden Markov model search method, depending on the availability of the matrix and actual sequenc...

Data on the structure and recognition properties of the template-selective binding sites in molecularly imprinted polymer membranes are presented. Porous molecularly imprinted polymer membranes based on semi-interpenetrating polymer networks (semi-IPN) were synthesized using the method of molecular imprinting in a combination with the method of com...

The operation of highly sensitive and selective multibiosensor based on different immobilized enzymes as bioselective elements and the matrix of pH-sensitive field effect transistors as transducers has been investigated. To develop bioselective elements of multibiosensor, the enzymes acetylcholinesterase, butyryl-cholinesterase, urease, glucose oxi...

The formation of noncanonical complexes of two eEF1A isoforms with different types of deacylated tRNAs was examined and apparent dissociation constants were measured. A higher affinity to tRNA was found for the tissue specific isoform of elongation factor eEF1A2, as compared with that of eEF1A1. For the first time the formation of noncanonic comple...

It is generally believed that basic features of ribosomal functions are universally valid, but a systematic test still stands out for higher eukaryotic 80S ribosomes. Here we report: (i) differences in tRNA and mRNA binding capabilities of eukaryotic and bacterial ribosomes and their subunits. Eukaryotic 40S subunits bind mRNA exclusively in the pr...

For the first time a conductometric biosensor for sucrose determination has been developed using a complex three-enzyme (invertase, mutarotase, and glucose oxidase) containing membrane as a sensitive element immobilized on the conductometric interdigitated planar electrodes. The time of measurement of sucrose concentration in the solution was about...

Three groups of the amperometric biosensors such as unmediated, mediated and based on direct transfer of electrons have been thoroughly described, and their advantages and disadvantages were shown. The amperometric biosensors are mostly utilized in commercial devices since they are studied to a greater extent and have some advantages. The modern co...

The theoretical principles of the conductometric method of measurements, the potentialities for the registration of enzymatic reactions, and examples of the application are shown. Various conductometric transducers for designing biosensors are described as well as methods of immobilization of an active material on the transducer surface, schemes, a...

Eukaryotic translation elongation factor eEF1A directs the correct aminoacyl-tRNA to ribosomal A-site. In addition, eEF1A is involved in carcinogenesis and apoptosis and can interact with large number of non-translational ligands. There are two isoforms of eEF1A, which are 98% similar. Despite the strong similarity, the isoforms differ in some prop...

The eEF1A1 and eEF1A2 isoforms of translation elongation factor 1A have 98% similarity and perform the same protein synthesis function catalyzing codon-dependent binding of aminoacyl-tRNA to 80S ribosome. However, the isoforms apparently play different non-canonical roles in apoptosis and cancer development which are awaiting further investigations...

The Cα-atoms trace root-mean-square deviation from the initial protein conformation. a, b – full protein, c, d – domain I, e, f – domain II, g, h – domain III. a, c, e, g – eEF1A1: red – trajectory 1, green – trajectory 2, blue – trajectory 3, cyan – trajectory 4, magenta – trajectory 5, yellow – trajectory 6. b, d, f, h – eEF1A2: red – trajectory...

Movie of eEF1A2 molecular dynamics, trajectory 9, cartoon representation. "Open" conformation is maintained.

Spatial model of human eEF1A2 with posttranslational modifications, in PDB format.

Movie of eEF1A2 molecular dynamics, trajectory 13, cartoon representation. "Closed" conformation is formed.

Movie of eEF1A1 molecular dynamics, trajectory 2, cartoon representation. "Open" conformation is maintained.

File in .txt format. Content of the file should be inserted to the end of ffg43a2.rtp file of GROMOS96 43a2 force field for supporting non-typical amino acid residues: N-methyllysine (MLZ), protonated N-methyllysine (MLZH), N-dimethyllysine (MLY), protonated N-dimethyllysine (MLYH), N-trimethyllysine (M3L) and L-glutamyl 5-glycerylphosphorylethanol...

File in text format. Content of the file should be inserted to the end of ffg43a2.hdb file of GROMOS96 43a2 force field for supporting non-typical amino acid residues: N-methyllysine (MLZ), protonated N-methyllysine (MLZH), N-dimethyllysine (MLY), protonated N-dimethyllysine (MLYH), N-trimethyllysine (M3L) and L-glutamyl 5-glycerylphosphorylethanol...

Spatial model of human eEF1A1 with posttranslational modifications, in PDB format.

Movie of eEF1A1 molecular dynamics, trajectory 6, cartoon representation. "Closed" conformation is formed.

The investigation presents the development of highly sensitive and selective multibiosensor based both on a number of immobilized enzymes as bioselective elements and the matrix of ion-selective field effect transistors as transducers of biochemical signal into the electric one. To develop bioselective elements of multi-biosensor, such enzymes as a...

We have used Far Western blot technique to determine several proteins from 60S ribosomal subunit from rabbit liver which are capable of interacting with homologous translation elongation factor 1A. They belong to phosphoprotein Р0.Р1/Р2 complex situated near A site region of 80S ribosome. It was also shown that eEF1A interacts with several proteins...

Two tissue-specific isoforms of mammalian translation elongation factor 1A, eEF1A1 and eEF1A2, are 98 % similar. However, some of their functions in the organism are different which in some cases could lead to the induction of carcinogenesis. We supposed that slight difference of primary sequences may cause significant differences of spatial struct...

Finding genes which have biologically meaningful ISRE (interferon-stimulated response element) is important for better understanding of the Jak-STAT activated cellular IFN response. We used transcription factor binding site (TFBS) search with gene orthology filtering to find putative ISREs in the promoters of protein-coding genes of Rattus norvegic...

A model of the eEF1A1 isoform of human translation elongation factor 1A has been proposed using a homology modelling method. The conformational mobility of eEF1A1 has been studied by means of multiple molecular dynamics simulation. The most essential coordinated motions in the protein have been identified using the covariance analysis of atom traje...

A novel electrochemical microbiosensor for protein determination based on an all-solid-state microelectrodes with a Ppy [3,3-Co(1,2-C2B9H11)2] solid internal contact and immobilized trypsin and carboxypeptidase B was developed. The specificity of the sensor signal was investigated using artificial ester and amide substrates of the proteinases: Nα-b...

Porous free-standing molecularly imprinted polymer membranes were synthesised by the method of in situ polymerisation using the principle of synthesis of interpenetrating polymer networks and tested in solid-phase extraction of triazine herbicides from aqueous solutions. Atrazine-specific MIP membranes were obtained by the UV-initiated co-polymeris...

A novel formaldehyde sensitive biosensor based on bacterial formaldehyde dehydrogenase (FDH) as a bio-recognition element has been developed. The bio-recognition membrane had bi-layer architecture and consisted of FDH, cross-linked with albumin, and of the cofactor NAD at a high concentration level (first layer). The second layer was a negatively c...

This paper describes authors' achievements in the development, investigation, and application of cholinesterase biosensors based on ISFETs. Various biosensors for determination of concentrations of different toxic substances (organophosphorous and carbamate pesticides, hypochlorite, glycoalkaloids) were designed on the basis of reversible and/or ir...

The key theoretical principles of the work on ion-selective field-effect transistor connected with their application in bioanalytical practice, some specifics of modern microtechnologies for their creation, and measurement schemes with set-ups are discussed. The achievements in the creation of enzyme biosensors based on ion-selective field-effect t...