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Protein glycosylation is a fundamental modification crucial for numerous intra- and extracellular functions in all eukaryotes. The phosphorylated dolichol (Dol-P) is utilized in N-linked protein glycosylation and other glycosylation pathways. Dolichol kinase (DK) plays a key role in catalyzing the phosphorylation of dolichol. The glycosylation patterns in the Kluyveromyces lactis DK mutant revealed that the yeast well tolerated a minor deficiency in Dol-P by adjusting protein glycosylation. Comparative analysis of sequences of DK homologs from different species of eukaryotes, archaea and bacteria and AlphaFold3 structural model studies, allowed us to predict that DK is most likely composed of two structural/functional domains. The activity of predicted K. lactis DK C-terminal domain expressed from the single copy in the chromosome was not sufficient to keep protein glycosylation level necessary for survival of K. lactis. However, the glycosylation level was partially restored by additionally provided and overexpressed N- or C-terminal domain. Moreover, co-expression of the individual N-and C-terminal domains restored the glycosylation of vacuolar carboxypeptidase Y in both K. lactis and Saccharomyces cerevisiae. Despite the differences in length and non-homologous sequences of the N-terminal domains the human and nematode Caenorhabditis elegans DKs successfully complemented DK functions in both yeast species. Additionally, the N-terminal domains of K. lactis and C. elegans DK could functionally substitute for one another, creating active chimeric enzymes. Our results suggest that while the C-terminal domain remains crucial for DK activity, the N-terminal domain may serve not only as a structural domain but also as a possible regulator of DK activity.

Protein glycosylation is a fundamental modification crucial for numerous intra- and extracellular functions in all eukaryotes. The phosphorylated dolichol (Dol-P) is utilized in N-linked protein glycosylation and other glycosylation pathways. Dolichol kinase (DK) plays a key role in catalyzing the phosphorylation of dolichol. The glycosylation patterns in the Kluyveromyces lactis DK mutant revealed that the yeast well tolerated a minor deficiency in Dol-P by adjusting protein glycosylation. Comparative analysis of sequences of DK homologs from different species of eukaryotes, archaea and bacteria and AlphaFold3 structural model studies, allowed us to predict that DK is most likely composed of two structural/functional domains. The activity of predicted K. lactis DK C-terminal domain expressed from the single copy in the chromosome was not sufficient to keep protein glycosylation level necessary for survival of K. lactis. However, the glycosylation level was partially restored by additionally provided and overexpressed N- or C-terminal domain. Moreover, co-expression of the individual N-and C-terminal domains restored the glycosylation of vacuolar carboxypeptidase Y in both K. lactis and Saccharomyces cerevisiae. Despite the differences in length and non-homologous sequences of the N-terminal domains the human and nematode Caenorhabditis elegans DKs successfully complemented DK functions in both yeast species. Additionally, the N-terminal domains of K. lactis and C. elegans DK could functionally substitute for one another, creating active chimeric enzymes. Our results suggest that while the C-terminal domain remains crucial for DK activity, the N-terminal domain may serve not only as a structural domain but also as a possible regulator of DK activity. [ABSTRACT FROM AUTHOR]

Here, the authors describe the emergence and spread of a new potential SARS-CoV-2 variant of interest, B.1.620. They show that this lineage, first identified in Lithuania, has established local transmission in Europe on multiple occasions and likely emerged in Central Africa.

Basalt polymers are rather new materials for civil engineering; therefore, identification of peculiarities and limitations of application of such polymers in concrete structures (particularly bridges) is of vital importance. This paper experimentally investigates deformation behaviour and cracking of flexural elements, which are predominant parameters governing serviceability of the bridges. Unlike a common practice, the present study is not limited by the analysis of concrete beams reinforced with the polymer bars; it also considers effectiveness of basalt fibre reinforced polymer sheets for repairing the beams. The analysis has revealed that a combination of the high strength and elasticity polymer materials governs the effective repair of the beams by significantly increasing (up to 40%) the structural stiffness.

Recombinant virus-like particles (VLPs) represent a promising tool for protein engineering. Recently, trichodysplasia spinulosa-associated polyomavirus (TSPyV) viral protein 1 (VP1) was efficiently produced in yeast expression system and shown to self-assemble to VLPs. In the current study, TSPyV VP1 protein was exploited as a carrier for construction of chimeric VLPs harboring selected B and T cell-specific epitopes and evaluated in comparison to hamster polyomavirus VP1 protein. Chimeric VLPs with inserted either hepatitis B virus preS1 epitope DPAFR or a universal T cell-specific epitope AKFVAAWTLKAAA were produced in yeast Saccharomyces cerevisiae. Target epitopes were incorporated either at the HI or BC loop of the VP1 protein. The insertion sites were selected based on molecular models of TSPyV VP1 protein. The surface exposure of the insert positions was confirmed using a collection of monoclonal antibodies raised against the intact TSPyV VP1 protein. All generated chimeric proteins were capable to self-assemble to VLPs, which induced a strong immune response in mice. The chimeric VLPs also activated dendritic cells and T cells as demonstrated by analysis of cell surface markers and cytokine production profiles in spleen cell cultures. In conclusion, TSPyV VP1 protein represents a new potential carrier for construction of chimeric VLPs harboring target epitopes.

Two novel polyomaviruses (PyVs) were identified in kidney and chest-cavity fluid samples of wild bank voles (Myodes glareolus) and common voles (Microtus arvalis) collected in Germany. All cloned and sequenced genomes had the typical PyV genome organization, including putative open reading frames for early regulatory proteins large T antigen and small T antigen on one strand and for structural late proteins (VP1, VP2 and VP3) on the other strand. Virus-like particles (VLPs) were generated by yeast expression of the VP1 protein of both PyVs. VLP-based ELISA and large T-antigen sequence-targeted polymerase-chain reaction investigations demonstrated signs of infection of these novel PyVs in about 42% of bank voles and 18% of common voles. In most cases only viral DNA, but not VP1-specific antibodies were detected. In additional animals exclusively VP1-specific antibodies, but no viral DNA was detected, indicative for virus clearance. Phylogenetic and clustering analysis including all known PyV genomes placed novel bank vole and common vole PyVs amongst members of the tentative Wukipolymavirus genus. The other known four rodent PyVs, Murine PyV and Hamster PyV, and Murine pneumotropic virus and Mastomys PyV belong to different phylogenetic clades, tentatively named Orthopolyomavirus I and Orthopolyomavirus II, respectively. In conclusion, the finding of novel vole-borne PyVs may suggest an evolutionary origin of ancient wukipolyomaviruses in rodents and may offer the possibility to develop a vole-based animal model for human wukipolyomaviruses.

Fiber reinforced polymers (FRPs) are considered to be a promising alternative to steel reinforcement, especially in concrete structures subjected to an aggressive environment or to the effects of electromagnetic fields. Although attempts to develop effective reinforcement have been followed, the application of FRPs remains limited by the solution to simple structural problems that mainly appear due to the absence of design codes, significant variation in the material properties of FRP composites and limited knowledge gained by engineers as regards the application aspects of FRP composites and structural mechanics of concrete elements reinforced with FRPs. To fill the latter gap, the current state-of-the-art report is dedicated to present recent achievements in FRPs applying practice to a broad engineers’ community. The report also revises the manufacturing process, material properties, the application area and design peculiarities of concrete elements reinforced with FRP composites. Along the focus on internal reinforcement, the paper overviews recent practices of applying FRP reinforced concrete (RC) elements in structural engineering. The review highlights the main problems restricting the application of FRPs in building industry and reveals the problematic issues (related to the material properties of the FRP) important for designing RC following the formulation of targets for further research.

Traditional steel reinforcement does not resist corrosion and its resources are limited; therefore, carbon, glass, aramid and basalt fibre reinforced polymer bars were developed. The composite reinforcement has a high tensile strength and resistance to electromagnetic fields. Different kinds of materials and application of various surface coatings are used in the production of the composite bars. This results in different adhesion to concrete and mechanical properties of composite bars. In comparison with steel reinforcement, glass, aramid and basalt fibre reinforced polymer bars have a lower modulus of elasticity. Thus, structural rigidity provided by these bars is smaller in respect to reinforced concrete elements. Current reinforced concrete design codes and recommendations are based on empirical and simplified methods of strain evaluation, which may be inadequate for design of structures with composite bars. In this paper, an adequacy of the empirical models was checked against the experimental data of concrete beams reinforced with composite bars. The moment-curvature data of 52 beams reported in the literature and conducted by the authors were used for assessment of accuracy of design methods. In order to perform the analysis, different methods from design codes (European (LST 2007), American (ACI Committee 318 2011) and Russian (NIIZhB 2006)) and recommendations (Italian (CNR 2007) and American (ACI Committee 440 2006)) have been selected. The results of the investigation will provide engineers with more information on design of concrete beams with fibre reinforced polymer bars. This will encourage an extensive use of these innovative materials in different types of structures. Santrauka Tradicinė plieninė armatūra nėra atspari korozijai, jos iŠtekliai yra riboti, todėl buvo sukurti polimeriniai strypai, armuoti anglies, stiklo, bazalto arba aramido pluoŠtu. Ši kompozitinė armatūra pasižymi dideliu tempiamuoju stipriu ir atsparumu elektromagnetiniam laukui. Kompozitinių strypų gamyboje naudojamos skirtingos medžiagos ir taikomi įvairūs pavirŠiaus dengimo būdai, skiriasi jų mechaninės bei sukibimo su betonu savybės. Lyginant su plienine armatūra, stiklo, aramido ir bazalto kompozitiniai strypų tamprumo modulis yra mažesnis, todėl tokiais strypais armuotų konstrukcijų standumas taip pat yra mažesnis nei gelžbetoninių konstrukcijų. Dabartiniuose gelžbetoninių konstrukcijų projektavimo reglamentuose taikomi empiriniai supaprastinti deformacijų nustatymo metodai gali būti netinkami konstrukcijoms, armuotoms polimerine armatūra, projektuoti. Šiame darbe, naudojant mokslinėse publikacijose surinktų 46 eksperimentinių tyrimų ir autorių atliktų 6 sijų bandymų duomenis, buvo įvertintas kompozitais armuoto betono elementų įlinkių skaičiavimo metodų tikslumas. Analizei atlikti buvo pasirinkti Europos (LST EN 1992-1-1:2005), JAV (ACI 318M-11) ir Rusijos (SP 52-101-2003) armuotojo betono konstrukcijų projektavimo normų bei Italijos (CNR-DT 203/2006) ir JAV (ACI 440.1R-06) projektavimo rekomendacijų metodai. Gauti analizės rezultatai suteiks projektuotojams iŠsamesnę informaciją apie kompozitais armuotų betoninių elementų projektavimą, skatins didins Šių inovatyvių medžiagų naudojimo apimtį įvairiose statybinėse konstrukcijose. Reikšminiai žodžiai: nemetalinė strypinė armatūra, projektavimo normos, eksperimentų duomenys, įlinkiai, armuotasis betonas, tikslumo analizė, trumpalaikė apkrova

The paper discusses the results of experimental and numerical modelling using two beams reinforced with GFRP bars. One beam was made of plain concrete while the other contained short steel fibres. The influence of steel fibres on deflection and cracking behaviour was studied. A comparative analysis of experimental results has shown that steel fibres significantly reduce deflections and average crack width of the beam. Moreover, an addition of steel fibres to the concrete mix led to a more ductile failure mode of the beam. Numerical analysis employing nonlinear finite element software ATENA has revealed that a good agreement between calculated and experimental results regarding an ordinary concrete GFRP reinforced beam can be obtained. Santrauka Kompozitinės armatūros taikymas betono konstrukcijoms dažnai sukelia šias problemas: neleistinai didelius įlinkius ir atsiveriančius plyšio pločius, trapų konstrukcijų irimą. Straipsnyje pateikiami dviejų vienodos geometrijos kompozitiniais stiklo pluošto strypais armuotų sijų eksperimentiniai ir skaitiniai tyrimai. Vienoje iš sijų į betono mišinį papildomai įdėta plieno plaušo fibrų. Bandymo metu matuoti vidutiniai sijų kreiviai, įlinkiai ir atsiveriantys plyšio pločiai. Atlikus lyginamąją analizę pastebėta, kad plieno plaušo naudojimas padidina stiklo pluoštu armuotų sijų standumą, atsparumą pleišėjimui, sijų suirimo pobūdis tampa plastiškesnis. Sijas sumodeliavus netiesine baigtinių elementų programa ATENA gautas geras eksperimentinių ir skaitinių rezultatų sutapimas įprasto betono stiklo pluošto armatūra armuotai sijai. Raktiniai žodžiai: armuotas betonas; stiklo pluošto armatūra; GFRP; pleišėjimas; eksperimentiniai tyrimai; skaitinis modeliavimas

Adequate modelling of reinforced concrete (RC) cracking, particularly post-cracking behaviour (tension stiffening), as one of the major sources of nonlinearity, is the most important and difficult task for deformation analysis. Deformationbehaviour of the cracked RC members is a complex process, including a wide range of effects such as differentstrength and deformation properties of steel and concrete, concrete cracking, tension-softening and tension-stiffening,bond slip between reinforcement and concrete etc. Even under low load, behaviour can be non-linear, which presents a challenge for calculating the deformations of RC members.When stress in concrete first reaches tensile strength at the weakest section,cracking occurs. After the formation of the first primary crack up to the final one, concrete contribution steadily decreases. At the final cracking point, the stable crack pattern has been reached. Increase in load will result in a further decrease of concrete contribution due to bond-slip causing cover-controlled cracks to develop between the primary cracks and a gradual breaking down of the bond. This process can be imagined as the formation of internal secondary cracks along the deformed bar due to bond stress transfer to sound concrete in between primary cracks. Total stresses in the cracked tensile reinforcement consisted of genuine stresses corresponding to the average strain of steel and additional stresses due to tension-stiffening. The internal forces that represent the latter stresses are called the residual and can be used for assessing the average bond behavior of RC members. This paper investigates tension-stiffening effect in RC members. The discrete cracking model of RC member is described in the paper. The discussed approach is based on bond-slip relationship that models the bond-action between concrete and reinforcement. This approach is realistically capable of modelling cracking and determining crack widths and deformations. However, the accuracy of calculation results depends on the assumed bond stress-slip relationship. A number of recent investigations aimed at developing and modifying such models were performed intending that discrete cracking modelling technique could become a powerful tool for the analysis of reinforced concrete members. The present study is dedicated to deformation analysis of reinforced members that are subjected to pure tension and is based on the results of the experimental program reported in literature. The average deformations of such members were calculated applying the discrete cracking method using different bond stress-slip relationships and compared with test results reported in literature. It was concluded that relationship recommended by CEB-FIP MC90 was unacceptable for the analysis performed. Tempiamųjų gelžbetoninių elementų diskrečiųjų plyšių modelio analizė Santrauka Šiame straipsnyje aptariamas gelžbetoninių elementų pleišėjimo diskretusis modelis. Pastaraisiais metais pleišėjimo diskretieji modeliai tobulinami ypač intensyviai tikintis, kad būtent šis modeliavimo būdas ateityje galėtų tapti universalia gelžbetoninių elementų projektavimo priemone. Analizuojamas modelis pagrįstas šlyties įtempių armatūros ir betono sąlyčio zonoje bei armatūros slinkties deformacijų priklausomybėmis. Taikant šį modelį galima apskaičiuoti plyšio plotį ir nustatyti deformacijų bei įtempių pasiskirstymą supleišėjusiame betone. Straipsnyje atliktas eksperimentinių tempiamųjų gelžbetoninių elementų modeliavimas bei parodyta, kad literatūroje rekomenduojamos šlyties įtempių sąlyčio zonoje ir armatūros slinkties idealizacijos gali buti netikslios. First Published Online: 16 May 2013 Reikšminiai žodžiai: gelžbetonis, diskretusis modelis, šlyties įtempiai, armatūros slinktis, deformacijos, pleišėjimas, tempiamieji elementai

Research reveals the diversity of the two Helicobacter pylori strains with respect to gene profile and the encoded DNA methyltransferases specificity. Twentyfive open reading frames are involved in the coding of the enzyme as evidenced by restriction analysis, homology searches, gene cloning and genomic mapping of the methylated bases.

Mathematical methods which estimate the arrangement of amino acids in the random sequence where analyzed here. The random sequence of amino acids can be used as a reading point for protein's similarities. It is important to choose rapid and accurate model for imitation of composition of random sequences.

The statistical analysis of oligonucleotide combinations and mathematical modelling of outgoing processes is very successfully used in the research. It present research we applied Markov chainmodel. Using themodel few new methodologies for research of oligonucleotidic composition within DNA sequenceswe created.

It was analyzed dependence of the average accuracy of secondary protein structure prediction on various GOR algorithm modifications. In essence new modification has expanded informational parameter set by taking into account secondary structure of neighboring amino acid. The accuracy of the method with this modification increases almost for 1 percent. This increase in accuracy is quite significant, as the amount of informational parameters increases not much.