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Trimetallic NiMoW/Al2O3 catalysts based on mixed H4[SiMonWn-12O40] (n = 1, 3, 6, and 9) Keggin-type heteropolyacids (HPAs) were synthesized by incipient wetness impregnation of alumina with aqueous solutions of mixed HPAs. For comparison purposes, trimetallic samples were prepared from a mixture of monometallic H4[SiMo12O40] and H4[SiW12O40 ] HPAs with a Mo/W ratio corresponding to the mixed MoW HPAs. The catalysts were sulfided by a liquid phase method and tested in the model reactions of dibenzothiophene hydrodesulfurization and naphthalene hydrogenation, with subsequent addition of quinoline to study the effect of inhibition of target reactions. Further, the catalysts were tested in the hydrotreating of straight-run gas oil to evaluate the efficiency of catalysts on real feedstocks. In order to link catalytic performances with the preparation method and Mo/W ratio, the catalysts were fully characterized by high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, high-angle annular dark-field imaging, and quick X-ray absorption spectroscopy. It was found that the Mo/W atomic ratio of the structure-forming metals in the active phase, deriving from the Mo/W ratio in the HPA precursor, directly affects the ratio of the hydrogenation and hydrodesulfurization performances. For feedstock with a high concentration of N-containing compounds, it is necessary to use mixed NiMoW systems with a high tungsten percentage to reduce the inhibitory effect and ensure the quality of the products. The use of new mixed MoW Keggin HPAs has made it possible to enhance the synergistic effect in trimetallic NiMoW catalysts due to the closer interaction between Mo and W, which increased the sulfidation degree of metals and also contributed to the formation of highly active mixed NiMoWS sites.

Recently, fluorescent proteins have become an indispensable tool for in vivo visualization of various processes occurring in living systems, from individual organelles to whole organisms. They allow observing the expression of proteins, their localization, and are also suitable for monitoring biochemical processes in cells. As a rule, fluorescent proteins have pH-dependent spectral properties, which make it possible to design genetically encoded pH sensors on their basis for solving various biological problems. In this work, we have obtained a set of extracellular pH sensors based on the SypHer3S protein, which has pH sensitivity in the pH range from 7.4 to 9.0. For this purpose, chimeric SypHer3S constructs with various transmembrane domains of membrane receptors were created, allowing the targeting of this protein to the outer side of the cytoplasmic membrane. Their subcellular localization was characterized and the most successful version of a chimeric pH sensor for measuring the extracellular pH value was selected.

Supported and unsupported (with or without Co and Ni promotors) MoS2-based catalysts were prepared using conventional incipient wetness impregnation method on pure and carbonized alumina with an appropriate aqueous solution of a 12-molybdophosphoric heteropolyacid and cobalt or nickel citrate. Unsupported MoS2 catalysts were synthesized by leaching away the supports from MoS2/Al2O3, MoS2/C/Al2O3 and using industrial CoMo/Al2O3 catalyst (named as Et-MoS2-Ind) with HF acid. Catalysts were investigated by low-temperature nitrogen adsorption and transmission electron microscopy techniques to characterize their structure and morphology. Catalysts were tested in hydrodeoxygenation (HDO) of oleic acid (OA) in an autoclave under hydrogen pressure. CoMoS2/Al2O3, NiMoS2/Al2O3, and Et-MoS2-Ind catalysts were also investigated as single and dual catalytic systems, using a bench-scale flow reactor in co-hydroprocessing of mixed feed, containing straight-run gas oil and 15 wt. % of waste sunflower oil. The results of the catalyst tests show that hydrogenation/decarbonylation (HYD/DEC) selectivity in oleic acid HDO strongly depends on catalyst type. The CoMoS2/C/Al2O3 and CoMoS2/Al2O3 catalysts show low HYD/(HYD + DEC) selectivity, equal to 0.55. Unpromoted MoS2/C/Al2O3, MoS2/Al2O3, Et-MoS2-Ind and Ref-MoS2 samples have quite similar HYD/(HYD + DEC) selectivity around 0.85. The highest HYD/(HYD + DEC) selectivity (0.95) was reached over Et-MoS2/C and Et-MoS2 samples, which indicated that HDO had gone through HYD route without any formation of CO and CO2. A double-bed catalyst reactor comprising of the upper-layer bulk Et-MoS2-Ind and the under-layer Co(Ni)–MoS2/Al2O3 catalysts are proposed for the effective co-hydroprocessing of diesel and vegetable oil.

The DNA-binding protein Dps plays a key role in the formation of Dps–DNA crystalline arrays in living bacterial cells, which allows bacteria to survive under stress conditions and under the influence of various adverse factors. Such genome-protective mechanisms can lead to the emergence of bacterial resistance to antibiotics and other drugs. Elucidation of the fundamental biochemical, genetic, and structural basis of the resistance is of primary importance for the development of strategies for combating and preventing bacterial resistance, as well as the elaboration of innovative therapeutic approaches. Conformational characteristics of Dps and its N-terminal fragments responsible for the nature of interactions of this protein with DNA in solution were studied by small-angle scattering.

Bimetallic catalysts MoW/СОK-12 are synthesized on the basis of mesostructured silicate COK‑12 prepared from sodium silicate aqueous solution using the Keggin structure hetero polyacid H4Si-Mo3W9O40 as an oxide precursor of the sulfide active phase and with the use of the mechanical mixture of two monometallic hetero polyacids (H4SiMo12O40 and H4SiW12O40) at a molar ratio of Mo/W = 3/9. Alumina-based analogs with the same surface metal content are used as reference samples. The test samples are analyzed by low-temperature nitrogen adsorption and high-resolution transmission electron microscopy. The catalytic activity is studied in the combined hydrotreatment of dibenzothiophene and naphthalene and in the hydrodesulfurization of 4,6-dimethyldibenzothiophene in a flow unit. It is shown that the use of mesostructured silicate COK-12 as a support leads to an increase in catalytic activity in target hydrotreating reactions.

International audience; A series of unsupported mono- and bimetallic MonW12-nS2 catalysts were synthesized by alumina elimination from supported MonW12-nS2/Al2O3 samples using acid etching. Alumina supported catalysts have been in turn prepared by using monometallic H4SiMo12O40 and H4SiW12O40 heteropolyacids (HPAs), their mixture with Mo/W atomic ratio equal to 1/11 and 3/9, and mixed bimetallic H4SiMo1W11O40 and H4SiMo3W9O40 HPAs. All catalysts were characterized by N2 adsorption, temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), time-of-flight secondary ion mass spectrometry (ToF-SIMS), extended X-ray absorption fine structure (EXAFS) spectroscopy and powder X-ray diffraction (XRD) and their performance were evaluated in simultaneous hydrodesulfurization (HDS) of dibenzothiophene (DBT) and hydrogenation (HYD) of naphthalene. The etching process led to a successful removal of all the support and of the partially sulfided species, with sulfidation degrees of both Mo and W above 90 % on the final bulk solids. The active phase also underwent a rearrangement, as higher average length and stacking were measured on the bulk catalysts than on the original supported ones. Mixed MoWS2 phase was evidenced in all solids, prepared from mixed HPAs (MonW12-nS2) or from the mixture of monometallic HPAs (RefMonW12-nS2), by EXAFS and ToF-SIMS, with however a larger quantity on the MoW solids. It seems that the mixed MoWS2 phase observed on the supported MoW catalysts is maintained through the etching process, while on RefMonW12-nS2 the mixed phase, observed in a much lesser extent in the corresponding supported catalyst, could result from the aggregation of the monometallic slabs. MonW12-nS2 catalysts were found more effective than the monometallic catalysts and than the corresponding RefMonW12-nS2, in both dibenzothiophene hydrodesulfurization and naphthalene hydrogenation, which was related to the presence of the mixed phase maintained through the etching of the support.

The determination of pH in live cells and tissues is of high importance in physiology and cell biology. In this report, we outline the process of the creation of SypHerExtra, a genetically encoded fluorescent sensor that is capable of measuring extracellular media pH in a mildly alkaline range. SypHerExtra is a protein created by fusing the previously described pH sensor SypHer3s with the neurexin transmembrane domain that targets its expression to the cytoplasmic membrane. We showed that with excitation at 445 nm, the fluorescence lifetime of both SypHer3s and SypHerExtra strongly depend on pH. Using FLIM microscopy in live eukaryotic cells, we demonstrated that SypHerExtra can be successfully used to determine extracellular pH, while SypHer3s can be applied to measure intracellular pH. Thus, these two sensors are suitable for quantitative measurements using the FLIM method, to determine intracellular and extracellular pH in a range from pH 7.5 to 9.5 in different biological systems.

A bulk MoWS2 catalyst has been synthesized by acid etching of the carrier from the supported MoWS2/Al2O3 catalyst obtained on the basis of the mixed bimetallic heteropoly acid (HPA) H4[SiMo3W9O40]. As reference samples, monometallic MoS2 and WS2 catalysts have been prepared from the corresponding supported analogues, as well as a Mo + WS2 sample based on a mechanical mixture of monometallic HPA in the atomic ratio of Mo/W = 1/3. The catalytic properties of the synthesized catalysts have been studied in model reactions of hydrodesulfurization (HDS) of dibenzthiophene (DBT) and hydrogenation (HYD) of naphthalene in a flow unit. It has been shown that the catalytic activity of the samples in both the DBT HDS and naphthalene HYD reactions increases in the following order: MoS2 < WS2 < Mo + WS2$$ \ll $$ MoWS2. It has been found that the bulk tungsten-containing catalysts exhibit higher specific catalytic activity than the supported counterparts. Increased values of hydrogen uptake according to the results of hydrogen temperature-programmed reduction for the bulk catalysts indicate an increase in the number of active sites and the formation of a more effective active phase compared to supported catalysts.

Trimetallic NiCoMo catalysts supported on γ-alumina (γ-Al2O3), amorphous silicon dioxide (SiO2), and mesostructured silicate (SBA-15) with equal surface concentration of active components were synthesized, and their physicochemical characteristics, including the morphology of the active phase particles, were studied. The performance of the synthesized catalysts in target hydrotreating reactions at different concentrations of an organic nitrogen-containing inhibitor, quinoline (0–1000 ppmw nitrogen), was determined. The inhibiting effect of quinoline on the hydrodesulfurization and hydrogenation reactions occurring on the synthesized catalysts and the influence of the kind and properties of the support on this effect were evaluated.

Mo(W)/SBA-15 catalysts are prepared using heteropoly acids H4SiMo12O40, H4SiW12O40, and H4SiMo3W9O40. The catalysts in the sulfide form are studied by low-temperature nitrogen adsorption, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalytic properties are tested in the hydrodesulfurization of 4,6-dimethyldibenzothiophene. It is shown that the gas-phase sulfiding of Mo(W)/SBA-15 catalysts leads to increase in the average length of particles and the number of Mo(W)S2 layers in active phase particles compared with liquid-phase sulfiding with the use of dimethyl sulfide. The replacement of a quarter of tungsten atoms with molybdenum ones makes it possible to considerably improve the catalytic activity of the mixed catalyst Mo + W/SBA-15 compared with the monometallic counterparts. This effect can be enhanced due to the use of mixed heteropoly acid H4SiMo3W9O40 as a precursor of the active phase of the MoW/SBA-15 catalyst, which is apparently associated with the formation of MoWS2 active sites.

Demetallization of a mixture of vacuum gas oil with heavy coker gas oil on CoMo/γ-Al2O3 catalysts with different pore structures was studied, and the influence of the catalyst pore structure on the process results was demonstrated. For the demetallization catalysts to be effective, their pore size should be restricted not only from below but also from above. When using samples with broad pores, effects of the hydrodesulfurization and hydrodemetallization inhibition can arise owing to adsorption of supramolecular structures of heavy residues, in particular, of asphaltenes.

A series of alumina supported CoMo catalysts with different molybdenum surface density was prepared using incipient wet impregnation method and applying H6[Co2Mo10O38H4] (Co2Mo10HPA) as a single oxidic precursor. Dried and sulfided catalysts were characterized by a variety of techniques, such as N2 adsorption, micro-Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron microscopy (HRTEM). Catalytic properties have been examined in co-hydrotreating of dibenzothiophene and naphthalene using a fixed bed high-pressure flow reactor. It was found that using Co2Mo10HPA as a single precursor enables more than the double increase of maximum metal loading compared to conventional compounds. This also contributed to a significant increase in catalytic activity in hydrotreating.

MoW alumina supported hydrotreating (HDT) catalysts were synthesized by using mixed SiMonW12-n heteropolyacids (HPAs) and also from a mixture of SiMo12 and SiW12 HPAs with the same Mo/W ratios for reference. Gas phase sulfidation of the catalysts prepared from mixed MoW HPAs led to the formation of a mixed phase evidenced by high-angle annular dark-field (HAADF) images, where a core of Mo atoms was surrounded by W atoms. Contrariwise, most of MoS2 or WS2 slabs were observed in the solids prepared from a mixture of the HPAs. This mixed phase induced higher hydrodesulfurization (HDS) of DBT, as well as hydrogenation (HYD) of naphthalene, than it was observed in the case of the reference catalysts. Comparison of activation procedures (gas phase versus liquid phase) confirmed that sulfidation in gas phase led to more efficient catalysts, even in the case of the formation of the mixed slabs. Beneficial effect of the mixed MoWS phase was even more pronounced in the case of the HDS of a more refractory molecule, 4,6-dimethyldibenzothiophene (4,6-DMDBT), which was attributed to the more hydrogenating properties of this mixed phase.

Under severe or prolonged stress, bacteria produce a nonspecific DNA-binding protein (Dps), which effectively protects DNA against damaging agents both in vitro and in vivo by forming intracellular biocrystals. The phenomenon of protective crystallization of DNA in living cells has been intensively investigated during the last two decades; however, the results of studies are somewhat contradictory, and up to now, there has been no direct determination of a Dps-DNA crystal structure. Here, we report the in vitro analysis of the vital process of Dps-DNA co-crystallization using two complementary structural methods: synchrotron small-angle X-ray scattering in solution and cryo-electron tomography. Importantly, for the first time, the DNA in the co-crystals was visualized, and the lattice parameters of the crystalline Dps-DNA complex were determined.

Supports based on pseudoboehmite, ultrastable zeolite Y, and ZSM-5 with different silica ratio and concentration of acid sites are prepared. NiMoS catalysts are synthesized by the incipient wetness impregnation of the prepared supports by the joint solution of H3PMo12O40 and nickel citrate. The composition and properties of the supports and catalysts are studied by low-temperature nitrogen adsorption, ammonia temperature-programmed desorption, IR spectroscopy of pyridine adsorption, and high-resolution transmission electron microscopy. Catalytic properties are investigated in dibenzothiophene hydrodesulfurization (HDS), naphthalene hydrogenation (HYD), and hexadecane hydrocracking (HC) concurrent reactions in a flow unit equipped with a microreactor. It is shown that the HDS activity of the synthesized samples declines as the dispersity of active-phase particles decreases in correlation with a change in the surface area of support mesopores. It is shown that the NiMo/ZSM-5/23 catalyst exhibits a high activity in naphthalene HYD and subsequent reactions of tetralin and decalin naphthene ring opening and hexadecane HC. It is found that the activity of zeolite-containing catalysts in naphthalene HYD grows with the proportion of Bronsted acid sites.

The catalytic properties of trimetallic NiMoWS catalysts supported on alumina are studied in the process of straight-run diesel fraction hydrotreating. It is shown that the nature of the oxide precursor of the mixed NiMoWS active phase strongly affects catalyst activity in the hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrogenation (HYD) of polycyclic aromatic hydrocarbons (PAH). The NiMoWS/Al2O3 catalyst synthesized from the mixed H4SiMo3W9O40 heteropoly acid is more efficient than the sample prepared from a mixture of individual H4SiMo12O40 and H4SiW12O40 heteropoly acids in both HDS and HDN transformations at the same metal content. The highest activity in PAH hydrogenation is exhibited by the NiMoWS/Al2O3 catalyst prepared using H4SiMo3W9O40.

The insulin receptor-related receptor (IRR) is a cellular sensor of a weakly alkaline medium. Its spatial structure and the mechanism of activation have not been yet established. In the present work, a system of heterologous expression of full-length IRR tyrosine kinase has been created. A plasmid construct encoding the cDNA of the full-length human IRR fused at the C-terminus with the green fluorescent protein (GFP) has been generated, and the hybrid protein has been expressed in HEK293 line cells. It has been shown that the receptor incorporated in the hybrid protein is expressed on the cytoplasmic membrane and retains its functional activity. The resulting protein can be used in further studies of the structure and function of IRR.

CoMoS/Cx/Sup Catalysts were prepared using 12-molybdophosphoric heteropolyacid and cobalt citrate. The supports were Al2O3, SiO2, nos, ZrO2, and carbonized Cr/Sup derived substrates (2 and 6 mass % carbon). The catalytic properties of these samples in the hydrodeoxygenation of guaiacol in a microflow apparatus were studied. With increasing carbon content in the supports, the length and number of MoS2 layers in the package increase in all the samples, apparently due to a decrease in the strength of the particle interaction with the more inert carbonized surface. Furthermore, the dispersion of the molybdenum particles on the catalyst surface, the content of promoter in the CoMoS active phase, and the extent of promotion of the crystallite edges differ significantly. The reasons were examined for the observed behavior and possible activity interrelationship during the hydrodeoxygenation of guaiacol with the parameters of the catalyst and active phase nanoparticles.

The effect of quinoline on the hydrodesulfurization and hydrogenation activities of bi- and trimetallic NiMo(W)/Al2O3 hydrotreating catalysts obtained using Keggin heteropoly acids H4SiMo3W9O40, H4SiMo12O40, and H4SiW12O40 (denoted as SiMo3W9, SiMo12, and SiW12, respectively) and a mixture of two monometallic heteropoly acids (SiMo12 and SiW12) was studied. The catalytic properties were determined in a fixed-bed microreactor in hydrotreating of model feedstock containing dibenzothiophene and naphthalene and of the same feedstock with the addition of quinoline. The trimetallic NiMoW/Al2O3 sample based on the mixed SiMo3W9 heteropoly acid exhibited 1.5 times higher catalytic activity in all the reactions studied compared to its analog prepared from a mixture of SiMo12 and SiW12 heteropoly acids with the same metal ratio. The trimetallic NiMoW/Al2O3 catalyst based on the mixed SiMo3W9 heteropoly acid surpassed in the activity the NiMo/Al2O3 sample and was more resistant to the inhibiting effect of quinoline than its analog prepared from a mixture of the two heteropoly acids. The correlations of the inhibiting effect of quinoline with the morphology of the active phase particles and the content of promoted active sites Ni(Mo)WS in the bi- and trimetallic NiMo(W)/Al2O3 catalysts were found.

It was recently found that the primary transcripts of some microRNA genes (pri-miRNAs) are able to express peptides with 12 to 40 residues in length. These peptides, called miPEPs, participate in the transcriptional regulation of their own pri-miRNAs. In our previous studies, we used bioinformatic approach for comparative analysis of pri-miRNA sequences in plant genomes to identify a new group of miPEPs (miPEP-156a peptides) encoded by pri-miR156a in several dozen species of the Brassicaceae family. Exogenous miPEP-156a peptides could efficiently penetrate into the plant seedlings through the root system and spread systemically to the leaves. The peptides produced moderate morphological effect accelerating primary root growth. In parallel, the miPEP-156a peptides upregulated expression of their own pri-miR156a. Importantly, the observed effects at both morphological and molecular levels correlated with the peptide ability to quickly translocate into the cell nucleus and to bind chromatin. In this work, we established secondary structure of the miPEP-156a and demonstrated its changes induced by formation of the peptide complex with DNA.

International journal of molecular sciences 22(11), 6056 (1-12) (2021). doi:10.3390/ijms22116056, Two independent, complementary methods of structural analysis were used to elucidate the effect of divalent magnesium and iron cations on the structure of the protective Dps-DNA complex. Small-angle X-ray scattering (SAXS) and cryo-electron microscopy (cryo-EM) demonstrate that Mg$^{2+}$ ions block the N-terminals of the Dps protein preventing its interaction with DNA. Non-interacting macromolecules of Dps and DNA remain in the solution in this case. The subsequent addition of the chelating agent (EDTA) leads to a complete restoration of the structure of the complex. Different effect was observed when Fe cations were added to the Dps-DNA complex; the presence of Fe$^{2+}$ in solution leads to the total complex destruction and aggregation without possibility of the complex restoration with the chelating agent. Here, we discuss these different responses of the Dps-DNA complex on the presence of additional free metal cations, investigating the structure of the Dps protein with and without cations using SAXS and cryo-EM. Additionally, the single particle analysis of Dps with accumulated iron performed by cryo-EM shows localization of iron nanoparticles inside the Dps cavity next to the acidic (hydrophobic) pore, near three glutamate residues., Published by Molecular Diversity Preservation International, Basel

International journal of biomedicine 11(Suppl_1), S7 (2021). doi:10.21103/IJBM.11.Suppl_1.OR2, Background: The effect of Dps-DNA co-crystals formation, which occurs in stressed Escherichia coli cells exposed to extreme conditions, is well described in the literature. However, the exact mechanisms of co-crystals formation are yet to be postulated remaining largely unknown. Here we summarize the results obtained by our group over the last few years using cryo-Electron Microscopy (cryo-EM) and Small Angle X-ray Scattering (SAXS). Methods: Samples for cryo-EM were plunge frozen in liquid ethane with Vitrobot Mark IV and studied with Titan Krios (ThermoFisher Scientific, US) cryo-EM, equipped with Falcon 2 direct electron detector, Image corrector (CEOS, Germany), and Volta phase plate. Single Particle Analysis (SPA) and cryo-Electron Tomography (cryo-ET) studies were conducted with 300 kV accelerating voltage in low dose mode using EPU and Tomography software (ThermoFisher Scientific, US). Cryo-EM data processing was conducted using Warp, CryoSPARC, IMOD, EMAN, and Relion software packages..., Published by International Medical Research and Development Corporation, New York, NY

To study the structure and function of the pH-regulated receptor tyrosine kinase insulin receptor-related receptor (IRR), а member of the insulin receptor family, we obtained six mouse monoclonal antibodies against the recombinant IRR ectodomain. These antibodies were characterized in experiments with exogenously expressed full-length IRR by Western blotting, immunoprecipitation, and immunocytochemistry analyses. Utilizing a previously obtained set of IRR/IR chimeras with swapped small structural domains and point amino acid substitutions, we mapped the binding sites of the obtained antibodies in IRR. Five of them showed specific binding to different IRR domains in the extracellular region, while one failed to react with the full-length receptor. Unexpectedly, we found that 4D5 antibody can activate IRR at neutral pH, and 4C2 antibody can inhibit activation of IRR by alkali. Our study is the first description of the instruments of protein nature that can regulate activity of the orphan receptor IRR and confirms that alkali-induced activation is an intrinsic property of this receptor tyrosine kinase.

On the basis of alumina synthesized via addition of mesostructured aluminum hydroxide gel, which is prepared by the hydrolysis of secondary aluminum butoxide in the presence of triblock copolymer Pluronic P123 to the AlOOH commercial powder, and the commercial reference sample, NiWS/Al2O3 catalysts are prepared using H3PW12O40 heteropolyacid and nickel citrate. The physicochemical properties of the supports and catalysts are studied by low-temperature nitrogen adsorption, temperature-programmed desorption of ammonia, and high-resolution transmission electron microscopy. The catalytic properties are investigated in the process of straight-run diesel fraction hydrotreating in a flow unit. It is shown that the use of the synthesized alumina as a catalyst support leads to an increase in the dispersity of nanosized particles of the NiWS active phase. The catalytic activity in targeted reactions also grows appreciably. The causes of these phenomena are discussed.

Unsupported molybdenum disulfide catalysts were synthesized from ammonium tetrathiomolybdate with chitosan, hexadecylammonium and Triton X100 as structural agents by leaching of MoS2/Al2O3 and MoS2/C/Al2O3 catalyst supports with HF acid and covering of “FeS” seeds by the MoS2 shell. Activation of the solids was performed under the H2S/H2 flow or by the decomposition of precursors in the presence of a hydrocarbon solvent in an autoclave reactor with varied H2 pressure. X-ray diffraction, N2 adsorption, temperature-programmed reduction, X-ray photoelectron spectroscopy and transmission electron microscopy techniques were used to characterize their structure and morphology. The nature of organic additives and activation conditions affect the surface area, pore size distribution, and morphological characteristics of MoS2 particles. Hydrodesulfurization of dibenzothiophene was performed in an autoclave reactor over unsupported MoS2based catalysts. The catalytic behavior of bulk MoS2 catalysts showed that the hydrogenation pathway prevailed over the direct desulfurization pathway. Higher HYD/DDS selectivity for dibenzothiophene hydrogenation was observed with the bulk molybdenum disulfide catalyst formed by etching of the MoS2/Al2O3 catalyst support. Unsupported Mo sulfide catalysts exhibited high hydrogenation activity in dibenzothiophene hydrodesulfurization and, therefore, might find wide applications in hydroprocessing of heavy feed and co-hydrotreating of petroleum fractions and plant oils.

CoMo hydrotreating catalysts with varied metal loading (1–4 Mo at nm− 2) based on Co2Mo10 heteropolyacid (HPA) and different supports (γ-Al2O3, SBA-15, SiO2) were prepared by incipient wetness impregnation. The catalysts were characterized by N2 physisorption, high resolution transmission electron microscopy (HRTEM), Raman and X-ray photoelectron spectroscopy (XPS). Catalytic activity was evaluated in co-hydrotreating (HDT) of the model feed containing dibenzothiophene (DBT) and naphthalene. The catalytic properties of CoMo catalysts were shown to depend on the morphological characteristics of CoMoS species, its promotion degree, and metal loading. The sulfidation degree of the initial precursor and effective cobalt amount in the CoMoS species increased with the Mo loading increase from 1 to 4 at nm− 2 in all studied catalysts. The DBT conversion maximum was achieved over CoMo/Al2O3 and CoMo/SBA-15 with 4 Mo at nm− 2. CoMo/SBA-15 catalysts had higher TOF numbers both in DBT HDS and in naphthalene hydrogenation (HYD) at the surface concentration of Mo same as in the other samples. These results can be attributed to optimal morphology of sulfide particles and the Co/Mo promotion degree due to a more suitable interaction between the active phase and support in mesoporous silica channels.

Reactivation of industrial CoMo/Al2O3 hydrotreating (HDT) catalysts was studied. A spent catalyst was used in the ULSD production for about 2.5 years. It was oxidatively regenerated and rejuvenated by organic acids (citric and thioglycolic), glycols (ethylene and triethylene), and dimethylsulfoxide solutions. All solids were characterized by the elemental analysis, N2 physisorption, X-ray powder diffraction, thermogravimetric analysis, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Changes in the active phase composition and morphology during the CoMo/Al2O3 HDT catalyst operation, regeneration and rejuvenation were shown. The rejuvenated catalysts were tested in hydrodesulfurization (HDS) of dibenzothiophene and hydrogenation (HYD) of naphthalene. It was found that oxidative regeneration allowed restoring about 70–85% rel. of initial activity. Rejuvenation with organic chemicals resulted in the complete restoration of HDS and HYD activities. Resulting catalytic activity of the reactivated catalysts depended on the properties of the formed active phase species. These correlations are discussed in the study.

СоМоS/Sup catalysts were prepared from 12-molybdophosphoric heteropoly acid and cobalt citrate, with Al2O3, SiO2, TiO2, and ZrO2 used as supports (Sup). The synthesized catalysts were studied by low-temperature nitrogen adsorption, X-ray diffraction, temperature-programmed ammonia desorption, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The catalytic properties of the catalysts were studied in a flow-through installation at 260 and 340°С, pressure of 3.0 MPa, feed space velocity of 80 h–1, and Н2/feed ratio of 500 Ln.c. L–1. The guaiacol hydrodeoxygenation rate increases with a decrease in the mean length of the active phase particles, irrespective of the kind of the oxide support. As for the support effect, the catalyst activity decreases in the order SiO2 > Al2O3 > ZrO2 ~ TiO2. On the other hand, the catalysts supported on ZrO2 and Al2O3 exhibit the highest stability. The causes of the observed trends and the possible relationships between the characteristics of the catalysts and active phase nanoparticles are discussed.

International audience; H4[SiMonW12−nO40] heteropolyacids (HPAs) are interesting precursors for the preparation of alumina-supported hydrotreatment catalysts to introduce both metals simultaneously while maintaining a Mo–W nanoscale proximity. Two heteropolyacids (n = 1 and 3) have been synthesized and used for the first time to prepare hydrotreatment catalysts. Crystal structure refinement has been performed and evidenced the formation of β-H4[SiMo3W9O40] with three ordered Mo sites forming a face. The purity of the samples in aqueous solution has been determined by Raman spectroscopy and polarographic characterization. These heteropolyacids were then impregnated on alumina to prepare supported MoW-based catalysts. As references, catalysts with the same Mo/W ratios have been prepared using monometallic H4SiMo12O40 and H4SiW12O40 HPAs (mixture of these 2 HPAs in the impregnating solution). EXAFS characterization after drying performed simultaneously at the Mo K and W LIII edges indicates preservation of the mixed heteropolyanion SiMonW12−nO404− at the alumina surface even if partial decomposition to Keggin lacunary species could not be excluded and evidences the mixed MoW–S2 slab formation after sulfidation. Better catalytic hydrogenation properties for dibenzothiophene hydrodesulfurization and naphthalene hydrogenation have been obtained when using β-H4[SiMo3W9O40], which is explained by the formation of the mixed MoW–S2 active phase.

In this paper, we present an approach to optimize the heterologous expression of the receptor tyrosine kinase IRR, which further simplifies the purification of the IRR from the medium and increases the final yield. The approach proposed by us can find application in the biotechnological production of other large-scale recombinant proteins produced for medical purposes.

Background: The insulin receptor-related receptor (IRR) was originally discovered due to its high homology to the other family members (insulin receptor and insulin-like growth factor 1 receptor). We determined that IRR can be activated by mildly alkaline extracellular media and has typical features of the ligand-receptor interaction, including its specificity and dose-dependence. Since pH-sensitive properties of IRR are determined by its ectodomain; therefore, we chose as an option to study the soluble extracellular domain IRR. Methods: The investigation carried out in Titan Krios 60-300 TEM/STEM (FEI, USA) CryoEM, equipped with direct electron detector Falcon II (FEI, USA) and Cs image corrector (CEOS, Germany), at an accelerating voltage of 300 kV. Data processing and 3D reconstruction were carried out using computing resources of the Federal Collective Usage Center Complex for Simulation and Data Processing for Mega-Science Facilities at NRC “Kurchatov Institute.” Results: The obtained 2D classifications of particles of the ectodomain IRR at a neutral pH form several 3D models. This indicates that the ectodomain has several possible conformations, which is consistent with our previously obtained data using SEC-SAXS and AFM. In the future, additional careful data processing is required, as well as studies of the IRR ectodomain in mildly alkaline pH. Conclusion: In this study, we presented the structural characteristics of the IRR ectodomain obtained by CryoEM. These results are an important step towards understanding the mechanism of functioning of the IRR.

Mono- and bimetallic Mo(W)S2 catalysts supported on γ-Al2O3 and SBA-15 have been prepared using the Keggin heteropoly acids (HPAs) H4SiMo12O40 and H4SiW12O40. The catalyst samples have been analyzed by temperature-programmed reduction with hydrogen, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalytic properties have been examined in the joint hydrotreating of dibenzothiophene and naphthalene on a flow-through unit. It has been shown that the use of mesoporous silica SBA-15 as a support can reduce the average length of Mo(W)S2 particles from 4.9 to 3.7 nm and increase the average number of layers and the particle size of the active phase, changes that lead to an increase in catalytic activity by a factor of ~3 relative to the alumina-supported counterparts. The use of a mixture of SiMo12HPA and SiW12HPA for preparing MoW catalysts leads to a significant enhancement of catalytic activity, which is apparently due to the formation of mixed active sites.

The bimetallic MoWS2/Al2O3 catalyst was synthesized using the Keggin-type mixed heteropolyacid H4SiMo3W9O40. The monometallic catalysts SiMo12/Al2O3 and SiW12/Al2O3 based on the H4SiMo12O40 and H4SiW12O40 acids are prepared as reference samples. The sulfidized catalysts are analyzed by temperature-programmed reduction with hydrogen, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Their catalytic properties are studied in the cohydrotreatment of dibenzothiophene (DBT) and naphthalene on a flow-type setup. The introduction of three molybdenum atoms into the structure of an oxide precursor is shown to increase the degree of sulfidation of the tungsten particles by 20% in comparison with SiW12/Al2O3. The DBT turnover frequency in the hydrodesulfurization (HDS) on the sites on the edges of the active phase of the SiMo3W9/Al2O3 catalyst is shown to be 5.5 times higher than in the presence of SiW12/Al2O3. The bimetallic sample demonstrated the highest selectivity in the preliminary DBT hydrogenation route and activity in the prehydrogenation of naphthalene. The high level of activity of the SiMo3W9/Al2O3 catalyst was due to the formation of a mixed Mo x W(1–x)S2 active phase with a MoW oxide precursor, whose structure contained both metals bonded at the molecular level.

The insulin receptor-related receptor (IRR) is the only known metabotropic sensor of extracellular alkaline medium involved in the regulation of the acid–base balance in the body. IRR is expressed in certain cell populations of the kidney, stomach, and pancreas that can come into contact with the extracellular fluids with alkaline pH. To study IRR structure and function, we obtained a stable hybridoma cell-line-producing antibody to the extracellular portion of the receptor. The monoclonal antibody isolated from ascitic fluids showed a positive reaction with the antigen in the ELISA test. The minimum working concentration of antibodies was 12.5 ng/mL. The ability of the antibodies to specifically recognize the purified ectodomain of IRR and the fulllength receptor was confirmed by western blot, immunoprecipitation, and immunocytochemistry.

The purpose of the study was to evaluate carbon effect on Co(Ni)-PMo/C/Al2O3 catalysts in co-hydrotreating (co-HDT) of straight-run gas oil (SRGO) and sunflower oil (SO). The catalysts were prepared using 12-molybdophosphoric heteropolyacid, cobalt tartrate, and Al2O3 or C/Al2O3 (2 wt% of carbon) as a support. The solids were characterized by N2 physisorption, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic properties were investigated using a bench-scale flow reactor in co-HDT of mixed feed containing SRGO and 5, 10, and 15 wt% of SO. It was found that Co-РMo catalysts demonstrated higher hydrodesulfurization (HDS) activity in SRGO HDT than its Ni-РMo/C/Al2O3 counterparts. The use of C/Al2O3 led to more active Co-РMo and Ni-РMo catalysts compared with Al2O3 supported ones. Co-PMo samples more significantly lost activities than Ni-PMo after adding SO in the feed. Addition of SO led to an increase in HDS apparent activation energy by 21 kJ mol−1 on Co-РMo and has not affected it in co-HDT of blended feedstock over Ni-PMo. All obtained results showed the high effectiveness of the prepared Ni-РMo/C/Al2O3 catalyst. They showed high HDS, hydrogenation and hydrodenitrogenation activities in co-HDT of the mixed SRGO/SO feedstock as well as catalyst stability against to accelerated deactivation. The possible reasons of the catalytic behavior of the studied samples are discussed based on the characteristics of the freshly sulfided and spent samples as well as determined kinetic parameters.

Trimetallic NiMoW/Al2O3 catalyst was prepared using mixed H4SiMo3W9O40 heteropoly acid of Keggin structure and nickel citrate. Bimetallic NiMo/Al2O3 and NiW/Al2O3 catalysts based on H4SiMo12O40 and H4SiW12O40, respectively, were synthesized as reference samples. The use of mixed H4SiMo3W9O40 heteropoly acid as an oxide precursor allows the tungsten sulfidation degree and the degree of promotion of active phase particles to be increased. The hydrodesulfurization activity is enhanced as compared to NiW/Al2O3 catalyst. The synergistic enhancement of the activity of the NiMo3W9/Al2O3 catalyst relative to the bimetallic analogs is probably caused by formation of new mixed promoted active sites for direct desulfurization.

The promoter nature effect on the sensitivity of Mo/Al2O3, Ni–Mo/Al2O3, Co–Mo/Al2O3, and Ni‒Co–Mo/Al2O3 catalysts to dodecanoic acid in the hydrotreating of a mixture containing dibenzothiophene and naphthalene has been investigated. The experiments have been carried out using a flow-through setup. The catalysts have been prepared using the PMo12 heteropoly acid, Сo(Ni) citrates, and Co2Mo10 heteropoly acid and have been characterized by high-resolution transmission electron microscopy. The highest hydrodesulfurization activity in the presence of dodecanoic acid is shown by the trimetallic catalyst Ni–Co–Mo/Al2O3. The introduction of Ni is favorable for dodecanoic acid conversion via the hydrogenation route, thus increasing the С11: С12 ratio in the conversion products. Effective dodecanoic acid adsorption constants under the hydrotreating conditions have been calculated using the Langmuir–Hinshelwood model.

CoPMo/Al2O3 catalysts were prepared using H3PMo12O40 and Co complexes with citric acid (CA) or non-complexing organic additives such as ethylene glycol (EG), diethylene glycol, triethylene glycol (TEG), glycerol, and a mixture of EG and CA. The catalysts were characterized by low-temperature N2 adsorption, Raman spectroscopy, thermogravimetric analysis, temperature-programmed reduction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The prepared samples were tested in hydrodesulfurization (HDS) of dibenzothiophene (DBT). The addition of either CA or glycols led to several beneficial effects such as weakening of the slab-support interaction at enhancing the promotion degree, dispersion and stacking number of the CoMoS species. It has been shown that the promotion degree of CoMoS edges increased with a pore volume gain by the additive-impregnated catalysts after their sulfidation. Catalysts with CA, TEG or the EG-CA mixture demonstrated higher activity in DBT HDS. Probable reasons for the found relationships are discussed.

Ni(Co)-PW/Al2O3 catalysts both unmodified and modified with potassium were synthesized with the use of H3PW12O40, CoCO3 or NiCO3, KOH and citric acid. The catalysts were characterized by the techniques such as low-temperature N2 adsorption, temperature-programmed reduction, X-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy. The prepared samples were tested in hydrotreating of model FCC gasoline that contained 1000 ppm of sulfur from thiophene and 36 wt.% of n-hexene-1 as a representative olefinic compound. The modification with an alkali metal influenced both the characteristics of the catalyst active phase and catalytic properties of (K)-Ni(Co)-PW/Al2O3 samples. The incorporation of potassium led to some l growth of the linear size of active phase crystallites, to a decrease of reactivity and of the number of active sites, to a strong decrease of CoWS and NiWS particle amounts with a simultaneous rise of separate CoSx and NiSx. The potassium addition also induced a drastic drop of hydrodesulfurization (HDS) and hydrogenation (HYDO) activity with a HDS/HYDO selectivity decrease for Ni- and Co-promoted systems and with a significant increase of the selectivity factor for unpromoted PW/Al2O3. The Ni-promoted catalyst proved to be more sensitive to the potassium modification than the Co-promoted one. So, the modified catalysts can be ranged by activity as follows: KWS

Pulsed laser deposition is often considered a process providing congruent transfer of target composition to the growing film. In fact, many different processes affect compositional preservation, starting from incongruent target ablation, to scattering on the way to the substrate, and to processes of the film formation on the substrate surface. We developed a pulsed laser deposition process trying to minimize the compositional deviations due to the scattering by the ambient gas by applying laser beam scanning across the target surface and substitution of oxygen with argon in the chamber during deposition. Transfer of elemental composition of YBa2Cu3O7 targets with compositions varying from stoichiometric 1/2/3 ratio was tested by deposition of thin films in conditions optimal for high-temperature superconductor formation. Despite all measures, the films still show Ba,Y enrichment due to different efficiencies of scattering on the ambient gas. The Y part in the film followed well the composition of the target, but the Ba enrichment was almost constant for most of the studied target compositions, implying a crucial role of the film growth processes. The YBa2Cu3O x (YBCO) films show a layered structure, with increased density of defects in the topmost layer. We suppose this is due to expelling of the excess Ba into the top layer with formation of a quasi-liquid layer promoting formation of a high-density YBCO film.

Co x -Co 2 Mo 10 /SiO 2 and Co 2 Mo 10 /Co x /SiO 2 catalysts with various Co/Mo ratios and active species compositions are prepared using H 6 [Co 2 Mo 10 O 38 H 4 ] heteropolyacid, CoCO 3 and citric acid. Catalysts are characterized using the following techniques: low-temperature N 2 adsorption, temperature-programmed reduction, high-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy. Catalytic activities of the synthesized catalysts are examined in hydrotreating of model fluid catalytic cracking (FCC) gasoline that contains 1000 ppm of sulphur from thiophene and 36 wt.% of n-hexene-1. As the Co/Mo ratio increases, hydrodesulphurization (HDS) and hydrogenation (HYD) activities of the prepared catalysts significantly builds up. The changes of catalytic properties and specifically of the HDS/HYDO selectivity factor of the synthesized CoMo catalysts arise from two effects: an alteration of the promotion degree of CoMoS active phase particles and a hydrogen spillover from CoS x species to active sites. The developed silica-supported CoMo catalysts may be a prospect for selective HDS and hydro-upgrading of FCC gasoline.

A deposition process for NdBa2Cu3O y thin films by laser ablation at decreased deposition temperature was developed using substitution of oxygen with argon in the chamber during deposition. A low deposition rate is the crucial factor to obtain high-quality NBCO films. The Nd/Ba cation disorder in the film can be suppressed by an increase of the deposition temperature or by a decrease of the oxygen partial pressure during deposition. The presence of Nd/Ba disorder during deposition stimulates the introduction of oxygen into the growing film. A simple model is proposed for estimation of oxygen contents in the film using structural parameters measured with XRD techniques. Studies of the post-deposition annealing process showed ordering of the Nd/Ba sub-lattice and intense oxygen in- and out-diffusion. The temperature of the post-deposition annealing step should be chosen low enough (∼400 °C) to avoid oxygen diffusion out of the NBCO film.

Rapid increase of intracellular synthesis of specific histone-like Dps protein that binds DNA to protect the genome against deleterious factors leads to in cellulo crystallization&mdash, one of the most curious processes in the area of life science at the moment. However, the actual structure of the Dps&ndash, DNA co-crystals remained uncertain in the details for more than two decades. Cryo-electron tomography and small-angle X-ray scattering revealed polymorphous modifications of the co-crystals depending on the buffer parameters. Two different types of the Dps&ndash, DNA co-crystals are formed in vitro: triclinic and cubic. Three-dimensional reconstruction revealed DNA and Dps molecules in cubic co-crystals, and the unit cell parameters of cubic lattice were determined consistently by both methods.

The radiation hardness results of light emitting diodes (LED) in green, blue and red regions of the spectrum and in white, based on InGaN, GaN and AlInGaP structures are presented. The technical aspects of monitoring parameters during exposure are described, and LEDs response to various radiation exposures are given.

Insulin receptor–related receptor (IRR) is a receptor tyrosine kinase of the insulin receptor family and functions as an extracellular alkali sensor that controls metabolic alkalosis in the regulation of the acid–base balance. In the present work, we sought to analyze structural features of IRR by comparing them with those of the insulin receptor, which is its closest homolog but does not respond to pH changes. Using small-angle X-ray scattering (SAXS) and atomic force microscopy (AFM), we investigated the overall conformation of the recombinant soluble IRR ectodomain (ectoIRR) at neutral and alkaline pH. In contrast to the well-known inverted U-shaped (or λ-shaped) conformation of the insulin receptor, the structural models reconstructed at different pH values revealed that the ectoIRR organization has a "droplike" shape with a shorter distance between the fibronectin domains of the disulfide-linked dimer subunits within ectoIRR. We detected no large-scale pH-dependent conformational changes of ectoIRR in both SAXS and AFM experiments, an observation that agreed well with previous biochemical and functional analyses of IRR. Our findings indicate that ectoIRR's sensing of alkaline conditions involves additional molecular mechanisms, for example engagement of receptor juxtamembrane regions or the surrounding lipid environment.

Background: It was shown that when exposed to extreme environment Dps-DNA co-crystallization takes place in Escherichia coli as a protective mechanism. However, to this date most of the proposed models of co-crystals were not backed up with any direct methods. Recent developments in Cryo Electron Tomography allow to visualize co-crystals with high spacial resolution in nearly native state. Methods: The investigations were carried out in a Titan Krios 60-300 TEM/STEM (FEI, USA) CryoEM, equipped with direct electron detector Falcon II (FEI, USA) and Cs image corrector (CEOS, Germany), at accelerating voltage of 300 kV. Tilt series were collected automatically using FEI Tomography software in low-dose mode which allowed to minimize the radiation damage. Subtomogram averaging was performed in Relion2 software package. Data processing and 3D reconstruction were carried out using computing resources of the Federal Collective Usage Center Complex for Simulation and Data Processing for Mega-Science Facilities at NRC “Kurchatov Institute”. Results: In this study, different types of Dps-DNA co-crystals were observed in vitro. Structural characteristics of the co-crystals were revealed for the first time by Cryo Electron Tomography. Subtomogram averaging allowed the direct visualization of Dps and DNA molecules in co-crystals. It was shown that the first type of co-crystals exhibits lamellar morphology and is formed by Dps layers alternating with DNA strands. The co-crystals adopt central symmetric triclinic crystal structure. The second type adopts body-centered cubic crystal lattice with mutually perpendicular DNA strands packed between Dps molecules. We assume that co-crystals’ structure could be dependent on the parameters of the utilized Dps and DNA solutions. Conclusion: In this study, we established structural characteristics of different types of Dps-DNA co-crystals. The obtained results are a vital step towards understanding the mechanism of protective Dps-DNA co-crystallization process.

International audience; Trimetallic CoMo3W9/Al2O3 catalyst is prepared using the Keggin structure mixed heteropolyacid H4SiMo3W9O40 and cobalt citrate. CoMo12/Al2O3 and CoW12/Al2O3 catalysts based on H4SiMo12O40 and H4SiW12O40, respectively, are synthesized as reference samples. Sulfided catalysts are analyzed by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Catalytic properties are investigated in the co-hydrotreatment of dibenzothiophene (DBT) and naphthalene in a flow unit. It is shown that the catalytic activity in both DBT hydrodesulfurization and naphthalene hydrogenation (HYD) decreases in the following sequence: CoMo12/Al2O3 > CoMo3W9/Al2O3 > CoW12/Al2O3, and it correlates with the degree of promotion of active-phase particles by cobalt atoms. A comparison with the published data available for Ni-promoted catalysts makes it possible to reveal the general regularity for bi- and trimetallic Со(Ni)-Mo(W)S catalysts: the use of mixed Mo-W H4SiMo3W9O40 heteropolyacid instead of monometallic H4SiW12O40 causes an increase in the degree of promotion of MoWS2 crystallite edges for the series of catalysts promoted by both cobalt and nickel. The use of nickel as a promoter leads to a higher degree of promotion of edges of active-phase particles in comparison with cobalt; as a result, the NiMo3W9/Al2O3 catalyst is much more active than the CoMo3W9/Al2O3 counterpart. Possible reasons behind the found features are discussed.

Journal of molecular biology 433(10), 166930 (2021). doi:10.1016/j.jmb.2021.166930, DNA co-crystallization with Dps family proteins is a fundamental mechanism, which preserves DNA in bacteria from harsh conditions. Though many aspects of this phenomenon are well characterized, the spatial organization of DNA in DNA���Dps co-crystals is not completely understood, and existing models need further clarification. To advance in this problem we have utilized atomic force microscopy (AFM) as the main structural tool, and small-angle X-scattering (SAXS) to characterize Dps as a key component of the DNA-protein complex. SAXS analysis in the presence of EDTA indicates a significantly larger radius of gyration for Dps than would be expected for the core of the dodecamer, consistent with the N-terminal regions extending out into solution and being accessible for interaction with DNA. In AFM experiments, both Dps protein molecules and DNA���Dps complexes adsorbed on mica or highly oriented pyrolytic graphite (HOPG) surfaces form densely packed hexagonal structures with a characteristic size of about 9 nm. To shed light on the peculiarities of DNA interaction with Dps molecules, we have characterized individual DNA���Dps complexes. Contour length evaluation has confirmed the non-specific character of Dps binding with DNA and revealed that DNA does not wrap Dps molecules in DNA���Dps complexes. Angle analysis has demonstrated that in DNA���Dps complexes a Dps molecule contacts with a DNA segment of ~6 nm in length. Consideration of DNA condensation upon complex formation with small Dps quasi-crystals indicates that DNA may be arranged along the rows of ordered protein molecules on a Dps sheet., Published by Elsevier, Amsterdam [u.a.]