Mikhail N Ryazantsev

St Petersburg State University

Rhodopsins are seven α-helical membrane proteins that are of great importance in chemistry, biology, and modern biotechnology. Any in silico study on rhodopsin properties and functioning requires a high-quality three-dimensional structure. Due to particular difficulties with obtaining membrane protein structures from the experiment, in silico predi...

A typical feature of proteins from the rhodopsin family is the sensitivity of their absorption band maximum to protein amino acid composition. For this reason, studies of these proteins often require methodologies that determine spectral shift caused by amino acid substitutions. Generally, quantum mechanics/molecular mechanics models allow for the...

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 u...

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 fluorescen...

Genetically encoded voltage indicators (GEVIs) have found wide applications as molecular tools for visualization of changes in cell membrane potential. Among others, several classes of archaerhodopsin-3-based GEVIs have been developed and have proved themselves promising in various molecular imaging studies. To expand the application range for this...

A novel method has been successfully developed for the synthesis of medium‐sized heterocycles containing thioamide groups. This approach facilitates the expansion of the imidazoline moiety within the condensed ring system through the action of S‐nucleophiles, enabling access to a broader and more diverse chemical space for natural product analogs a...

The idea of preparation a water‐soluble Pt‐containing AIEgen was successfully realized by direct reversible addition‐fragmentation transfer copolymerization of a Pt(II) complex (LPtPV) containing a vinyl group and polyvinylpyrrolidone (p(VP)). The resulting block‐copolymer p(VP‐b‐LPtPV) containing 5–8 Pt(II) chromophores exhibits intriguing photoph...

The heteroatom nature in 10‐membered enediynes plays a crucial role in tuning of their reactivity in the Bergman cyclization, which is a decisive factor for the biological activity of enediynes. Although benzothiophene‐fused O‐ and N‐enediynes have been identified as promising biological objects, the corresponding thiaenediyne remains unknown. To f...

The structural features and luminescent properties of heterometallic Tb–Gd, Tb–La, and Tb–Y terephthalate metal–organic frameworks, namely (TbxM1−x)2(1,4-bdc)3∙4H2O (M = Gd, La, Y), were studied in detail in a wide concentration range (x = 0.001–1). The crystalline phase of synthesized compounds corresponds to Ln2(1,4-bdc)3·4H2O. The lifetime of 5D...

New heterometallic antenna terephthalate MOFs, namely, (EuxM1−x)2bdc3·4H2O (M = Y, La, Gd) (x = 0.001–1), were synthesized by a one-step method from aqueous solutions. The resulting compounds are isomorphic to each other; the crystalline phase corresponds to Ln2bdc3∙4H2O. Upon 300 nm excitation to the singlet excited state of terephthalate ions, al...

We report the development of a convenient organocatalytic method for the synthesis of 5H‐pyrano[3,2‐c]chromenes from chromone‐containing acrylates and ethyl cyanoacetate. The synthesis is characterized by simple conditions (ethanol, basic catalysis) and good yields (up to 90 %). The synthesized pyrano[3,2‐c]chromenes are a promising new class of fl...

In this work, three series of micro-sized heterometallic europium-containing terephthalate MOFs, (Eu1-xLnx)2bdc3·nH2O (Ln = La, Gd, Lu), are synthesized via an ultrasound-assisted method in an aqueous medium. La3+ and Gd3+-doped terephthalates are isostructural to Eu2bdc3·4H2O. Lu3+-doped compounds are isostructural to Eu2bdc3·4H2O with Lu contents...

Cu-Catalyzed azide-alkyne cycloaddition (CuAAC) in the case of 1-iodoalkynes has been known as a synthetic tool towards 5-iodo-1,2,3-triazole derivatives. We found that CuAAC of 1-iodobuta-1,3-diynes and aryl azides under CuI(PPh3)3...

A simple and efficient technique for voltammetric enzymeless detection of epinephrine (EP) is proposed. The technique applies hierarchical Ru-based electrodes modified by Au nano- to micro-sized particles, which were produced with laser-assisted synthesis. The cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were employed to charact...

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, recently proposed several classes of engineered rhodopsins with enhanced fluorescence along with the discovery of a new natural highly fluorescent...

Fluorescent isocoumarin‐fused cycloalkynes, which are reactive in SPAAC and give fluorescent triazoles regardless of the azide nature, have been developed. The key structural feature that converts the non‐fluorescent cycloalkyne/triazole pair to its fluorescent counterpart is the pi‐acceptor group (COOMe, CN) at the C6 position of the isocoumarin r...

The series of luminescent NaYF4:Sm3+ nano- and microcrystalline materials co-doped by La3+, Gd3+, and Lu3+ ions were synthesized by hydrothermal method using rare earth chlorides as the precursors and citric acid as a stabilizing agent. The phase composition of synthesized compounds was studied by PXRD. All synthesized materials except ones with hi...

Luminescent, heterometallic terbium(III)–lutetium(III) terephthalate metal-organic frameworks (MOFs) were synthesized via direct reaction between aqueous solutions of disodium terephthalate and nitrates of corresponding lanthanides by using two methods: synthesis from diluted and concentrated solutions. For (TbxLu1−x)2bdc3·nH2O MOFs (bdc = 1,4-benz...

We report the synthesis and investigation of Au–Ru composite with highly developed specific surface area exhibiting excellent electrocatalytic performance suitable for detection of such hydrophobic metabolites as epinephrine in the physiological environment. This electrode material was fabricated using two-stage laser-assisted metal deposition tech...

NMDA receptors play critical roles in numerous physiological and pathological processes in CNS that requires development of modulating ligands. In particular, photoswitchable compounds that selectively target NMDA receptors would be particularly useful for analysis of receptor contributions to various processes. Recently, we identified a light-depe...

A new series of luminescent heterometallic europium(III)–lutetium(III) terephthalate metal–organic frameworks, namely (EuxLu1−x)2bdc3·nH2O, was synthesized using a direct reaction in a water solution. At the Eu3+ concentration of 1–40 at %, the MOFs were formed as a binary mixture of the (EuxLu1−x)2bdc3 and (EuxLu1−x)2bdc3·4H2O crystalline phases,...

Two series of β-NaYF4:Ln3+ nanoparticles (Ln = La–Nd, Sm–Lu) containing 20 at. % and 40 at. % of Ln3+ with well-defined morphology and size were synthesized via a facile citric-acid-assisted hydrothermal method using rare-earth chlorides as the precursors. The materials were composed from the particles that have a shape of uniform hexagonal prisms...

Copper is an inexpensive material that has found wide application in electronics due to its remarkable electric properties. However, the high toxicity of both copper and copper oxide imposes restrictions on the application of this metal as a material for bioelectronics. One way to increase the biocompatibility of pure copper while keeping its remar...

Azobenzene/tetraethyl ammonium photochromic ligands (ATPLs) are photoactive compounds with a large variety of photopharmacological applications such as nociception control or vision restoration. Absorption band maximum and lifetime of the less stable isomer are important characteristics that determine the applicability of ATPLs. Substituents allow...

The use of laser methods for synthesizing new materials for non-enzymatic electrochemical microsensors for express analysis of biological fluids is a promising scientific question. Laser-induced chemical liquid phase deposition is the laser deposition of invisible miniature bimetallic deposits from aqueous solutions of salts and complexes of transi...

In the search for fundamentally new, active, stable, and readily synthetically accessible cycloalkynes as strain-promoted azide-alkyne cycloaddition (SPAAC) reagents for bioorthogonal bioconjugation, we integrated two common approaches: the reagent destabilization by the increase of a ring strain and the transition state stabilization through elect...

The luminescent coarse-, micro- and nanocrystalline europium(III) terephthalate tetrahydrate (Eu2bdc3‧4H2O) metal-organic frameworks were synthesized by the ultrasound-assisted wet-chemical method. Electron micrographs show that the europium(III) terephthalate microparticles are 7 μm long leaf-like plates. According to the dynamic light scattering...

We investigated the influence of morphology of Ni microstructures modified with Au and Pt on their cell biocompatibility and electrocatalytic activity toward non-enzymatic glucose detection. Synthesis and modification were carried out using a simple and inexpensive approach based on the method of laser-induced deposition of metal microstructures fr...

Photopharmacology is a field of medicine and pharmacology that uses light to selectively activate or deactivate pharmaceutical agents. This approach significantly enhances and localizes the drug action and, therefore, reduces its side effects. Apart from the bioactive moiety, any photopharmacological compound should contain a photoactive group that...

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., interaction of metal electrodes with biological mat...

In this paper, we propose a fast and simple approach for the fabrication of the electrocatalytically active ruthenium-containing microstructures using a laser-induced metal deposition technique. The results of scanning electron microscopy and electrical impedance spectroscopy (EIS) demonstrate that the fabricated ruthenium-based microelectrode had...

A simple approach for in situ laser-induced modification of iridium-based materials to increase their electrocatalytic activity towards enzyme-free glucose sensing was proposed. For this purpose, we deposited gold and platinum separately and as a mixture on the surface of pre-synthesized iridium microstructures upon laser irradiation at a wavelengt...

Quantum mechanics/Molecular mechanics (QM/MM) models are widely used tool to obtain a detailed insight into the properties and functioning of proteins. The outcome of QM/MM studies heavily depends on the quality of an applied QM/MM model. Prediction and right placement of internal water molecules in protein cavities is one of the critical parts of...

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

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

The ultrafast photochemistry of the [Cr(NCS)6]³⁻ complex upon excitation to the ⁴T2 ligand-field (LF) state was studied in dimethylsulfoxide (DMSO) and N,N-dimethylformamide (DMF) in a wide temporal range (100 fs – 9 ms) by a combination of femtosecond and nanosecond transient absorption spectroscopy techniques and supported by quantum-chemical DFT...

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 i...

In this work, we reported in situ laser-induced synthesis of sensor-active copper‑silver microcomposite. This bimetallic microelectrode exhibits highly developed surface area and good electrical conductivity, and can be successfully used for glucose and alanine sensing demonstrating decent sensitivity (31,000 μА cm⁻² mМ⁻¹ for d-glucose and 11,177 μ...

Optogenetics and photopharmacology are two perspective modern methodologies for control and monitoring of biological processes from an isolated cell to complex cell assemblies and organisms. Both methodologies use optically active components that being introduced into the cells of interest allow for optical control or monitoring of different cellul...

A simple, efficient and atom-economic method has been developed for the synthesis of complex alkaloid-like compounds with spiro-fused indolo[2,1-b]quinazoline and cyclopropa[a]pyrrolizine or 3-azabicyclo[3.1.0]hexane moieties. We have found that one-pot, three-component 1,3-dipolar cycloaddition reactions allow the desired products to be obtained f...

We report one-step in situ laser-induced synthesis of the conductive copper microstructures doped with iron, zinc, nickel, and cobalt with highly developed surface area. It was observed that the presence of chlorides of the aforementioned metals in the solutions used in our experiments increases the deposition rate and the amount of copper in the r...

Technologies that allow restoring lost vision are a long-held dream of the humanity. In order to fulfill this dream many scientific problems have to be solved. Here, we review modern technologies of vision restoration paying special attention to retinal prosthesis technologies: Argus, Alpha IMS, Intelligent Medical Implant, Artificial Silicon Retin...

Application of molecular photochromic ion channel blockers to recover the visual function of a degenerated retina is one of the promising trends in photopharmacology. To this day, several photochromic azobenzene-based compounds have been proposed and their functionality has been demonstrated on cell lines and knockout mouse models. Further advance...

Application of molecular photochromic ion channel blockers to recover the visual function of a degenerated retina is one of the promising trends in photopharmacology. To this day, several photochromic azobenzene-based compounds have been proposed and their functionality has been demonstrated on cell lines and knockout mouse models. Further advance...

It was demonstrated in recent studies that some rhodopsins can be used in optogenetics as fluorescent indicators of membrane voltage. One of the promising candidates for these applications is archaerhodopsin-3. While it has already shown encouraging results, there is still a large room for improvement. One of possible directions is increasing the i...

A simple and efficient method has been developed for the synthesis of complex compounds with spiro-fused 11H-indeno[1,2-b]quinoxaline and cyclopropa[a]pyrrolizine or azabicyclo[3.1.0]hexane moieties. All the products have been synthesized in good to high yields and excellent diastereoselectivity by one-pot three-component 1,3-dipolar cycloaddition...

In this work we demonstrate the role of a ligand in formation of the conductive and electrocatalytically active copper microstructures produced using the in situ laser-induced metal deposition technique. For this purpose, the alkaline solutions of different concentrations containing copper(II) chloride and Rochelle salt, which is used as ligand and...

The synthesis of conductive gold and copper-gold microstructures with high developed surface based on the method of laser-induced metal deposition from solution was developed. The topology and crystallization phase of these structures were observed by means of scanning electron microscopy and X-ray diffraction, respectively. The electrochemical pro...

It was demonstrated in recent studies that some rhodopsins can be used in optogenetics as fluorescent indicators of membrane voltage. One of the promising candidates for these applications is archaerhodopsin-3. However, the fluorescent signal for wild-type achaerhodopsin-3 is not strong enough for real applications. Rational design of mutants with...

It was demonstrated in recent studies that some rhodopsins can be used in optogenetics as fluorescent indicators of membrane voltage. One of the promising candidates for these applications is archaerhodopsin-3. However, the fluorescent signal for wild-type achaerhodopsin-3 is not strong enough for real applications. Rational design of mutants with...

A simple and efficient strategy is reported for the synthesis of anthracene-fused isoxazolopyrrolo[2,1-a]isoquinolines via an endocyclic N-acyliminium ion cyclization. The cyclization of 18-aryl-21-(2-arylethyl)-22-hydroxy-16-oxa-17,21-diazahexacyclo[6.6.5.315,19.02,7.09,14.015,19]docosa-2,4,6,9,11,13,17-heptaen-20-ones proceeds with high stereosel...

Detailed kinetic models (DKMs) are the most fundamental "bottom-up" approaches to computational investigation of the pyrolysis and oxidation of fuels. The weakest points of existing DKMs are incomplete information about the reaction types that can be involved in the potential energy surfaces (PESs) in pyrolysis and oxidation processes. Also, the co...

The crossed molecular beam reactions of the meta-tolyl radical with 1,3-butadiene and D6-1,3-butadiene were conducted at collision energies of 48.5 kJ mol(-1) and 51.7 kJ mol(-1). The reaction dynamics propose a complex-forming reaction mechanism via addition of the meta-tolyl radical with its radical center either to the C1 or C2 carbon atom of th...

The crossed molecular beam reactions of para-tolyl (C7H7) plus 1,3-butadiene (C4H6), para-tolyl (C7H7) plus 1,3-butadiene-d6 (C4D6) and para-tolyl-d7 (C7D7) plus 1,3-butadiene (C4H6) were carried out under single collision conditions at collision energies of about 55 kJ mol-1. The 7-methyl-1,4-dihydronaphthalene was identified as the major reaction...