Artículos de revistas: "Functional and Structural cycle"

1

Hao, Zhitao, Xi’an Li, Rongrong Gao, Wang Yao, Yukun Wang, Wenqi Zhao y Hongbo Sang. "Study on Shear Behavior and Mechanism Based on Shear Functional Unit of Loess Microstructure". Sustainability 15, n.º 14 (22 de julio de 2023): 11402. http://dx.doi.org/10.3390/su151411402.

Texto completo

Resumen

The structural specificity and hydrological sensitivity of loess have a strong impact on its long-term stability and safety. This topic is being actively researched and focuses on the macromechanical behavior of the shear strength of loess disturbed and its micromechanisms from the perspective of the dry–wet cycle (especially involving soluble salt erosion). In this paper, the correlation between micro-structural shear functional units and macroscopic degradation behavior was established by combining the changes in physicochemical properties of mass loss, surface cracking, strength deterioration, and structural disturbance of the loess with scanning electron microscopy (SEM) microscopic images in different dry–wet cycles and different salt contents. Results revealed that with the increase in dry–wet cycles and salt content, the mass loss of soil deteriorated and the surface crack rate increased. The cohesion of soil showed an overall decreasing trend, which decreased more obviously in the early stage of the dry–wet cycle, followed by a slow decrease, and tended to be constant after nine dry–wet cycles. However, the internal friction angle increased and then decreased during the whole cycle, and its value generally changed little. According to the deterioration and decay of shear strength, it can be concluded that the structural disturbance of loess increased with the increase in dry–wet cycles and salt content. At the same time, further linear quantization fitting of the structural disturbance parameters showed that the structural parameters had a positive correlation with salt content and a power function with dry–wet cycles, where dry–wet cycles seemed to play a dominant role in the loess structural deterioration rather than salt content. The microscopic study demonstrates that the dry–wet cycles and salt content do not directly affect the cohesion and internal friction angle of soil but change the basic shear structural unit of aggregate and then cause an essential impact on c and φ, which in turn have an essential impact on soil strength attenuation. This paper not only helps to elucidate the essence of water–soil–salt structural interactions but also provides theoretical references for sustainable development research in environmental engineering, geological engineering, and other related fields.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Naryzhny, S. N. y O. K. Legina. "Structural-functional diversity of p53 proteoforms". Biomeditsinskaya Khimiya 65, n.º 4 (agosto de 2019): 263–76. http://dx.doi.org/10.18097/pbmc20196504263.

Texto completo

Resumen

Protein p53 is one of the most studied proteins. This attention is primarily due to its key role in the cellular mechanisms associated with carcinogenesis. Protein p53 is a transcription factor involved in a wide variety of processes: cell cycle regulation and apoptosis, signaling inside the cell, DNA repair, coordination of metabolic processes, regulation of cell interactions, etc. This multifunctionality is apparently determined by the fact that p53 is a vivid example of how the same protein can be represented by numerous proteoforms bearing completely different functional loads. By alternative splicing, using different promoters and translation initiation sites, the TP53 gene gives rise to at least 12 isoforms, which can additionally undergo numerous (>200) post-translational modifications. Proteoforms generated due to numerous point mutations in the TP53 gene are adding more complexity to this picture. The proteoforms produced are involved in various processes, such as the regulation of p53 transcriptional activity in response to various factors. This review is devoted to the description of the currently known p53 proteoforms, as well as their possible functionality.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Llorca, Oscar, Sergio Marco, José L. Carrascosa y José M. Valpuesta. "Conformational Changes in the GroEL Oligomer during the Functional Cycle". Journal of Structural Biology 118, n.º 1 (febrero de 1997): 31–42. http://dx.doi.org/10.1006/jsbi.1996.3832.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Tie, J. K. y D. W. Stafford. "Structural and functional insights into enzymes of the vitamin K cycle". Journal of Thrombosis and Haemostasis 14, n.º 2 (29 de enero de 2016): 236–47. http://dx.doi.org/10.1111/jth.13217.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Ohya, Y. y Y. Anraku. "Yeast calmodulin: Structural and functional elements essential for the cell cycle". Cell Calcium 13, n.º 6-7 (junio de 1992): 445–55. http://dx.doi.org/10.1016/0143-4160(92)90057-y.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Asribekova, M. K. y L. B. Kalimullina. "Structural and functional organization of the amygdala during the estrous cycle". Bulletin of Experimental Biology and Medicine 107, n.º 6 (junio de 1989): 878–81. http://dx.doi.org/10.1007/bf00840768.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Wang, Yingying, Yu Feng y Weiming Zeng. "Non-Rigid Cycle Consistent Bidirectional Network with Transformer for Unsupervised Deformable Functional Magnetic Resonance Imaging Registration". Brain Sciences 15, n.º 1 (5 de enero de 2025): 46. https://doi.org/10.3390/brainsci15010046.

Texto completo

Resumen

Background: In neuroscience research about functional magnetic resonance imaging (fMRI), accurate inter-subject image registration is the basis for effective statistical analysis. Traditional fMRI registration methods are usually based on high-resolution structural MRI with clear anatomical structure features. However, this registration method based on structural information cannot achieve accurate functional consistency between subjects since the functional regions do not necessarily correspond to anatomical structures. In recent years, fMRI registration methods based on functional information have emerged, which usually ignore the importance of structural MRI information. Methods: In this study, we proposed a non-rigid cycle consistent bidirectional network with Transformer for unsupervised deformable functional MRI registration. The work achieves fMRI registration through structural MRI registration, and functional information is introduced to improve registration performance. Specifically, we employ a bidirectional registration network that implements forward and reverse registration between image pairs and apply Transformer in the registration network to establish remote spatial mapping between image voxels. Functional and structural information are integrated by introducing the local functional connectivity pattern, the local functional connectivity features of the whole brain are extracted as functional information. The proposed registration method was experimented on real fMRI datasets, and qualitative and quantitative evaluations of the quality of the registration method were implemented on the test dataset using relevant evaluation metrics. We implemented group ICA analysis in brain functional networks after registration. Functional consistency was evaluated on the resulting t-maps. Results: Compared with non-learning-based methods (Affine, Syn) and learning-based methods (Transmorph-tiny, Cyclemorph, VoxelMorph x2), our method improves the peak t-value of t-maps on DMN, VN, CEN, and SMN to 18.7, 16.5, 16.6, and 17.3 and the mean number of suprathreshold voxels (p < 0.05, t > 5.01) on the four networks to 2596.25, and there is an average improvement in peak t-value of 23.79%, 12.74%, 12.27%, 7.32%, and 5.43%. Conclusions: The experimental results show that the registration method of this study improves the structural and functional consistency between fMRI with superior registration performance.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Sekhar, Ashok, Rina Rosenzweig, Guillaume Bouvignies y Lewis E. Kay. "Mapping the conformation of a client protein through the Hsp70 functional cycle". Proceedings of the National Academy of Sciences 112, n.º 33 (3 de agosto de 2015): 10395–400. http://dx.doi.org/10.1073/pnas.1508504112.

Texto completo

Resumen

The 70 kDa heat shock protein (Hsp70) chaperone system is ubiquitous, highly conserved, and involved in a myriad of diverse cellular processes. Its function relies on nucleotide-dependent interactions with client proteins, yet the structural features of folding-competent substrates in their Hsp70-bound state remain poorly understood. Here we use NMR spectroscopy to study the human telomere repeat binding factor 1 (hTRF1) in complex with Escherichia coli Hsp70 (DnaK). In the complex, hTRF1 is globally unfolded with up to 40% helical secondary structure in regions distal to the binding site. Very similar conformational ensembles are observed for hTRF1 bound to ATP-, ADP- and nucleotide-free DnaK. The patterns in substrate helicity mirror those found in the unfolded state in the absence of denaturants except near the site of chaperone binding, demonstrating that DnaK-bound hTRF1 retains its intrinsic structural preferences. To our knowledge, our study presents the first atomic resolution structural characterization of a client protein bound to each of the three nucleotide states of DnaK and establishes that the large structural changes in DnaK and the associated energy that accompanies ATP binding and hydrolysis do not affect the overall conformation of the bound substrate protein.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Anderson, Jan M. y W. S. Chow. "Structural and functional dynamics of plant photosystem II". Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 357, n.º 1426 (29 de octubre de 2002): 1421–30. http://dx.doi.org/10.1098/rstb.2002.1138.

Texto completo

Resumen

Given the unique problem of the extremely high potential of the oxidant P + 680 that is required to oxidize water to oxygen, the photoinactivation of photosystem II in vivo is inevitable, despite many photoprotective strategies. There is, however, a robustness of photosystem II, which depends partly on the highly dynamic compositional and structural heterogeneity of the cycle between functional and non–functional photosystem II complexes in response to light level. This coordinated regulation involves photon usage (energy utilization in photochemistry) and excess energy dissipation as heat, photoprotection by many molecular strategies, photoinactivation followed by photon damage and ultimately the D1 protein dynamics involved in the photosystem II repair cycle. Compelling, though indirect evidence suggests that the radical pair P + 680 Pheo – in functional PSII should be protected from oxygen. By analogy to the tentative oxygen channel of cytochrome c oxidase, oxygen may be liberated from the two water molecules bound to the catalytic site of the Mn cluster, via a specific pathway to the membrane surface. The function of the proposed oxygen pathway is to prevent O 2 from having direct access to P + 680 Pheo – and prevent the generation of singlet oxygen via the triplet–P 680 state in functional photosytem IIs. Only when the, as yet unidentified, potential trigger with a fateful first oxidative step destroys oxygen evolution, will the ensuing cascade of structural perturbations of photosystem II destroy the proposed oxygen, water and proton pathways. Then oxygen has direct access to P + 680 Pheo – , singlet oxygen will be produced and may successively oxidize specific amino acids of the phosphorylated D1 protein of photosystem II dimers that are confined to appressed granal domains, thereby targeting D1 protein for eventual degradation and replacement in non–appressed thylakoid domains.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Berzal-Herranz, Alfredo, Cristina Romero-López, Beatriz Berzal-Herranz y Sara Ramos-Lorente. "Potential of the Other Genetic Information Coded by the Viral RNA Genomes as Antiviral Target". Pharmaceuticals 12, n.º 1 (13 de marzo de 2019): 38. http://dx.doi.org/10.3390/ph12010038.

Texto completo

Resumen

In addition to the protein coding information, viral RNA genomes code functional information in structurally conserved units termed functional RNA domains. These RNA domains play essential roles in the viral cycle (e.g., replication and translation). Understanding the molecular mechanisms behind their function is essential to understanding the viral infective cycle. Further, interfering with the function of the genomic RNA domains offers a potential means of developing antiviral strategies. Aptamers are good candidates for targeting structural RNA domains. Besides its potential as therapeutics, aptamers also provide an excellent tool for investigating the functionality of RNA domains in viral genomes. This review briefly summarizes the work carried out in our laboratory aimed at the structural and functional characterization of the hepatitis C virus (HCV) genomic RNA domains. It also describes the efforts we carried out for the development of antiviral aptamers targeting specific genomic domains of the HCV and the human immunodeficiency virus type-1 (HIV-1).

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Piatak, T. V. y I. A. Fedorenko. "A mechanism for evaluating and forecasting the financial stability of an enterprise". Economic Herald of SHEI USUCT 20, n.º 2 (2024): 79–87. https://doi.org/10.32434/2415-3974-2024-20-2-79-87.

Texto completo

Resumen

During of the study, a mechanism for evaluating and forecasting the financial stability of an enterprise based on a process approach has been proposed. The created mechanism provides for modeling the financial sustainability of enterprise using an integrated model of the functional and structural organization of enterprise, which allows to establish the necessary relationships between the structural units of enterprise in the course of production cycles. It has been proposed to consider the financial stability of an enterprise in a broad and narrow sense for each production cycle during of its implementation. In the narrow sense, the financial stability of an enterprise has been considered as the ability to ensure solvency for current obligations at the expense of own and borrowed funds. In the broad sense, it has been proposed to consider financial stability as a process of repeatability of production cycles with control over the ratio of positive and negative cash flows in the dynamics. In the whole enterprise, financial stability has been proposed to be defined as the weighted average ratio of positive and negative cash flows. The use of this mechanism involves selecting the optimal number and value of factors that affect the planned financial result in the future by the method of successive approximations. The process approach involves the use of a model of the functional-structural organization of the enterprise to obtain the distribution of production cycles according to its optimal structure. The optimal structure is the functional-necessary structure, which contains the minimum set of elements of the production structure that ensures the execution of all production cycles with the duration determined in the mono-mode. The preparatory stage for building the functional-necessary structure is the normalization procedure, which ensures the determination of the conditions of connection between individual elements of the production cycle. For each production cycle, a set of absolute and relative financial indicators is established that have optimal values and determine the type of financial stability of the enterprise as a whole. It has been proposed to determine the type of financial stability of an enterprise as a whole by obtaining probabilities of financial stability for each production cycle, taking into account the share of the enterprise’s resources that is directed to the implementation of a specified production cycle.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Häuβler, S., M. Rohde, N. von Neuhoff, M. Nimtz y I. Steinmetz. "Structural and Functional Cellular Changes Induced by Burkholderia pseudomallei Rhamnolipid". Infection and Immunity 71, n.º 5 (mayo de 2003): 2970–75. http://dx.doi.org/10.1128/iai.71.5.2970-2975.2003.

Texto completo

Resumen

ABSTRACT In this study we report that extracellular Burkholderia pseudomallei rhamnolipid induced cytopathic changes characterized by retraction, rounding up, and, finally, detachment in phagocytic and nonphagocytic cell lines. These changes were due to a progressive reorganization of the F-actin network resulting in impaired cell cycle progression and a reduced phagocytic function of macrophages.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

Kalinina, O. V. y A. V. Dmitriev. "Structural and functional genome organization and life cycle of hepatitis C virus". Molecular Genetics, Microbiology and Virology 30, n.º 2 (abril de 2015): 64–70. http://dx.doi.org/10.3103/s0891416815020044.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Zhong, Xiao Ping, Wei Liang Jin y Wen Xue. "Life-Time Index in Whole Structural Life-Cycle". Advanced Materials Research 243-249 (mayo de 2011): 5711–16. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.5711.

Texto completo

Resumen

In the analysis on whole structural life-cycle, there are two important factors to need to be considered. One is the determination of design service life of structure, and another is design of structure based on service life. After analyzing deeply the influence factors of life-time index, it can be found that the design service life of structure not only depends on technology level, functional requirement and economic cost factors of structures, but also relate with the specific environmental conditions, using conditions and maintenance conditions of structures. So that, an analysis method of determined design service life of structure is given in this paper. For design of structure on service life, from the view of whole structural life-cycle, a probability reliability-based analysis method of structural service life design and re-design is proposed in this paper. By updating constantly design parameters, the correctness of predicted service life is improved gradually.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Ishii, K. "Life-Cycle Engineering Design". Journal of Mechanical Design 117, B (1 de junio de 1995): 42–47. http://dx.doi.org/10.1115/1.2836469.

Texto completo

Resumen

Life-cycle engineering seeks to incorporate various product life-cycle values into the early stages of design. These values include functional performance, manufacturability, serviceability, and environmental impact. We start with a survey of life-cycle engineering research focusing on methodologies and tools. Further, the paper addresses critical research issues in life-cycle design tools: design representation and measures for life-cycle evaluation. The paper describes our design representation scheme based on a semantic network that is effective for evaluating the structural layout. Evaluation measures for serviceability and recyclability illustrate the practical use of these representation schemes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Ishii, K. "Life-Cycle Engineering Design". Journal of Vibration and Acoustics 117, B (1 de junio de 1995): 42–47. http://dx.doi.org/10.1115/1.2838675.

Texto completo

Resumen

Life-cycle engineering seeks to incorporate various product life-cycle values into the early stages of design. These values include functional performance, manufacturability, serviceability, and environmental impact. We start with a survey of life-cycle engineering research focusing on methodologies and tools. Further, the paper addresses critical research issues in life-cycle design tools: design representation and measures for life-cycle evaluation. The paper describes our design representation scheme based on a semantic network that is effective for evaluating the structural layout. Evaluation measures for serviceability and recyclability illustrate the practical use of these representation schemes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Zaloilo, I., Y. Rud, О. Zaloilo y L. Buchatskyi. "Coronavirus viroporins: structure and function". Ukrainian Biochemical Journal 93, n.º 1 (22 de febrero de 2021): 5–17. http://dx.doi.org/10.15407/ubj93.01.005.

Texto completo

Resumen

Viroporins are involved in viral pathogenesis, play an important role in the morphogenesis of virions and ensure their release from the infected cell. These proteins are potentially promising as possible targets for the regulation of virus reproduction. The literature data on the current understanding of coronavirus viroporins functioning are summarized in the review. Special attention is focused on specific structural features that determine the functional ability of these proteins. The basic principles of viroporins localization in the cell and their influence on the coronavirus life cycle are considered. Keywords: coronavirus, pore formation, protein 3a, protein 8a, protein E, SARS, viroporins

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Jain, Sahil, Ekaterina Martynova, Albert Rizvanov, Svetlana Khaiboullina y Manoj Baranwal. "Structural and Functional Aspects of Ebola Virus Proteins". Pathogens 10, n.º 10 (15 de octubre de 2021): 1330. http://dx.doi.org/10.3390/pathogens10101330.

Texto completo

Resumen

Ebola virus (EBOV), member of genus Ebolavirus, family Filoviridae, have a non-segmented, single-stranded RNA that contains seven genes: (a) nucleoprotein (NP), (b) viral protein 35 (VP35), (c) VP40, (d) glycoprotein (GP), (e) VP30, (f) VP24, and (g) RNA polymerase (L). All genes encode for one protein each except GP, producing three pre-proteins due to the transcriptional editing. These pre-proteins are translated into four products, namely: (a) soluble secreted glycoprotein (sGP), (b) Δ-peptide, (c) full-length transmembrane spike glycoprotein (GP), and (d) soluble small secreted glycoprotein (ssGP). Further, shed GP is released from infected cells due to cleavage of GP by tumor necrosis factor α-converting enzyme (TACE). This review presents a detailed discussion on various functional aspects of all EBOV proteins and their residues. An introduction to ebolaviruses and their life cycle is also provided for clarity of the available analysis. We believe that this review will help understand the roles played by different EBOV proteins in the pathogenesis of the disease. It will help in targeting significant protein residues for therapeutic and multi-protein/peptide vaccine development.

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Oliveira, F. R. M., M. G. Silva y V. Gomes. "Exploring life cycle-based sustainability indicators for building structural frames in concrete". Revista IBRACON de Estruturas e Materiais 6, n.º 5 (octubre de 2013): 832–43. http://dx.doi.org/10.1590/s1983-41952013000500008.

Texto completo

Resumen

This paper aims at advancing on the validation of indicators of building concrete frames' sustainability from an integrated, life cycle perspective. A case study approach investigates (i) feasibility of comparing sustainability performance of different flooring systems; and (ii) similarity between environmental indicators trends for a typical flooring system and corresponding whole superstructure. Three residential buildings are analyzed, using either prestressed concrete flat (PCF) slabs or reinforced concrete waffle (RCW) slabs and flat beams exposed to a marine environment. SimaPro 7.3 supports calculation of the environmental indicators. Service life estimation is used to ensure functional equivalence and to form a basis for life cycle costing. PCF slabs showed best functional/technical and economic results but were outperformed by RCW slabs' environmental results. Most environmental indicators showed the same trend for both typical floor and whole superstructure.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Lu, Xianlu, Xuenan Pan, Dongdong Zhang, Zhi Fang, Shang Xu, Yu Ma, Qiao Liu et al. "Robust high-temperature potassium-ion batteries enabled by carboxyl functional group energy storage". Proceedings of the National Academy of Sciences 118, n.º 35 (24 de agosto de 2021): e2110912118. http://dx.doi.org/10.1073/pnas.2110912118.

Texto completo

Resumen

The popularly reported energy storage mechanisms of potassium-ion batteries (PIBs) are based on alloy-, de-intercalation-, and conversion-type processes, which inevitably lead to structural damage of the electrodes caused by intercalation/de-intercalation of K+ with a relatively large radius, which is accompanied by poor cycle stabilities. Here, we report the exploration of robust high-temperature PIBs enabled by a carboxyl functional group energy storage mechanism, which is based on an example of p-phthalic acid (PTA) with two carboxyl functional groups as the redox centers. In such a case, the intercalation/de-intercalation of K+ can be performed via surface reactions with relieved volume change, thus favoring excellent cycle stability for PIBs against high temperatures. As proof of concept, at the fixed working temperature of 62.5 °C, the initial discharge and charge specific capacities of the PTA electrode are ∼660 and 165 mA⋅h⋅g−1, respectively, at a current density of 100 mA⋅g−1, with 86% specific capacity retention after 160 cycles. Meanwhile, it delivers 81.5% specific capacity retention after 390 cycles under a high current density of 500 mA⋅g−1. The cycle stabilities achieved under both low and high current densities are the best among those of high-temperature PIBs reported previously.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Naureen, Irum, Aisha Saleem, Hafiza Hira Rehman, Umar farooq, Iqra Iqbal, Tayyaba Sehar y Tahir Ali. "Intrinsically Disordered Proteins, Structural and Functional Dynamics". Scholars International Journal of Biochemistry 5, n.º 1 (21 de enero de 2022): 8–14. http://dx.doi.org/10.36348/sijb.2022.v05i01.002.

Texto completo

Resumen

The classical theory is that before being biologically active, proteins are assembled into a unique three-dimensional structure in terms of quality. These Intrinsically Disordered Proteins (IDPs) are very common in many genomes, including humans and play a key role in central cell processes such as transcription and translation, cell cycle, and cell signaling regulation. In addition, the proportion of proteins associated with various diseases such as cancer and neurodegenerative diseases is very high in IDPs. Therefore, considerable efforts have been made to elucidate the molecular mechanisms supporting the role of IDPs in Biology and disease through the use of experimental and computational methods. Animal models are needed for human genetic anatomy and better treatment options. Genetic disease Although some animals are used key models in academic and industrial research .There is a lot of stress in the anatomy of genetic diseases. The Genetic resemblance of rats and the humans from which is naturally occurring genetic disease, unique population. The availability of structure and complete genomic sequencing has made purebred dogs a powerful model. Used for disease research. The main advantage of dogs is that they suffer from about 450 genetic diseases, of which about half show significant medical symptoms, Similar to the same human disease. Therefore, these two facts make dogs an ideal medical practice, and a genetic model. This review sheds light on some of them, common genetic disease, in dog model. In this article plays an important role in identifying the genes responsible for the disease and / or the use of new genes, treatment of interest for dogs and humans.

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Nierhaus, Knud H., Dieter Beyer, Marylena Dabrowski, Markus A. Schäfer, Christian M. T. Spahn, Jörg Wadzack, Jörg-Uwe Bittner et al. "The elongating ribosome: structural and functional aspects". Biochemistry and Cell Biology 73, n.º 11-12 (1 de diciembre de 1995): 1011–21. http://dx.doi.org/10.1139/o95-108.

Texto completo

Resumen

We determined the positions and arrangements of RNA ligands within the ribosome with a new neutron-scattering technique, the proton-spin contrast-variation. Two tRNAs were bound to the ribosome in the pre-translocational and the post-translocational state. The mass centre of gravity of both tRNAs resides at the subunit interface of the body of the 30S subunit. Both tRNAs are separated by an angle of 50–55°, and their mutual arrangement does not change during translocation. The mass centre of gravity moves by 13 ± 3Å(1Å = 0.1 nm) during translocation, corresponding well with the length of one codon. Using an RNase-digestion technique, the length of the mRNA sequence covered by the ribosome was determined to be 39 ± 3 nucleotides before and after translocation. The ribosome moves like a rigid frame along the mRNA during translocation. In contrast, both tRNAs seem to be located on a movable ribosomal domain, which carries the tRNAs before, during, and after translocation, leaving the microtopography of the tRNAs with the ribosome unaltered. This conclusion was derived from an analysis of the contract patterns of thioated tRNAs on the ribosome. The results have led to a new model of the elongation cycle, which reinterprets the features of the previous "allosteric three-sites model" in a surprisingly simple fashion. Finally, a mutational analysis has identified a single nucleotide of the 23S rRNA essential for the peptidyltransferase activity.Key words: tRNA–ribosomal contacts, neutron scattering, location of tRNAs in ribosomes, movement of ribosome on mRNA, peptidyltransferase.

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Heller Murray, Elizabeth S., Roxanne K. Segina, Geralyn Harvey Woodnorth y Cara E. Stepp. "Relative Fundamental Frequency in Children With and Without Vocal Fold Nodules". Journal of Speech, Language, and Hearing Research 63, n.º 2 (26 de febrero de 2020): 361–71. http://dx.doi.org/10.1044/2019_jslhr-19-00058.

Texto completo

Resumen

Purpose Relative fundamental frequency (RFF) is an acoustic measure that is sensitive to functional voice differences in adults. The aim of the current study was to evaluate RFF in children, as there are known structural and functional differences between the pediatric and adult vocal mechanisms. Method RFF was analyzed in 28 children with vocal fold nodules (CwVN, M = 9.0 years) and 28 children with typical voices (CwTV, M = 8.9 years). RFF is the instantaneous fundamental frequency ( f 0 ) of the 10 vocalic cycles during devoicing (vocal offset) and 10 vocalic cycles during the revoicing (vocal onset) of the vowels that surround a voiceless consonant. Each cycle's f 0 was normalized to a steady-state portion of the vowel. RFF values for the cycles closest to the voiceless consonant, that is, Offset Cycle 10 and Onset Cycle 1, were examined. Results Average RFF values for Offset Cycle 10 and Onset Cycle 1 did not differ between CwVN and CwTV; however, within-subject variability of Offset Cycle 10 was decreased in CwVN. Across both groups, male children had lower Offset Cycle 10 RFF values as compared to female children. Additionally, Onset Cycle 1 values were decreased in younger children as compared to those of older children. Conclusions Unlike previous work with adults, CwVN did not have significantly different RFF values than CwTV. Younger children had lower RFF values for Onset Cycle 1 than older children, suggesting that vocal onset f 0 may provide information on the maturity of the laryngeal motor system.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Sánchez, E., J. Teixidó, R. Guerrero y R. Amils. "Hypersensitivity of Rhodobacter sphaeroides ribosomes to protein synthesis inhibitors: structural and functional implications". Canadian Journal of Microbiology 40, n.º 9 (1 de septiembre de 1994): 699–704. http://dx.doi.org/10.1139/m94-111.

Texto completo

Resumen

The elongation cycle of protein synthesis systems of purple nonsulfur photosynthetic bacteria Rhodobacter sphaeroides, grown both phototrophically and chemotrophically, was studied using 33 inhibitors with different chemical structures and functional and domain specificities. No functional differences between phototrophic and chemotrophic ribosomal systems were detected. Rhodobacter sphaeroides ribosomes exhibited strong hypersensitivity to nine functional inhibitors when compared with Escherichia coli ribosomes. Most of the R. sphaeroides ribosomal hypersensitivities corresponded to peptidyltransferase inhibitors, implying that this important functional neighborhood must be somehow different in the two organisms.Key words: protein synthesis inhibitors, ribosomal function, peptidyltransferase, photosynthetic bacteria.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Zhang, Ling, Yinghui Wang, Hong Dai y Jie Zhou. "Structural and functional studies revealed key mechanisms underlying elongation step of protein translation". Acta Biochimica et Biophysica Sinica 52, n.º 7 (13 de mayo de 2020): 749–56. http://dx.doi.org/10.1093/abbs/gmaa046.

Texto completo

Resumen

Abstract The ribosome is an ancient and universally conserved macromolecular machine that synthesizes proteins in all organisms. Since the discovery of the ribosome by electron microscopy in the mid-1950s, rapid progress has been made in research on it, regarding its architecture and functions. As a machine that synthesizes polypeptides, the sequential addition of amino acids to a growing polypeptide chain occurs during a phase called the elongation cycle. This is the core step of protein translation and is highly conserved between bacteria and eukarya. The elongation cycle involves codon recognition by aminoacyl tRNAs, catalysis of peptide bond formation, and the most complex operation of translation—translocation. In this review, we discuss the fundamental results from structural and functional studies over the past decades that have led to understanding of the three key questions underlying translation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Szyk, Agnieszka, Alexandra Deaconescu, Grzegorz Piszczek y Antonina Roll-Mecak. "Tubulin tyrosine ligase - structural and functional studies". Acta Crystallographica Section A Foundations and Advances 70, a1 (5 de agosto de 2014): C479. http://dx.doi.org/10.1107/s2053273314095205.

Texto completo

Resumen

Microtubules are polymers essential for cell morphogenesis, cell division and intracellular transport. This polymer's basic building block is the α/β tubulin heterodimer, which associates head-to-tail and laterally to form the microtubule. Tubulin is subject to diverse, abundant and evolutionarily conserved post-translational modifications that mark subpopulations of microtubules. The highest density and variety of post-translational modifications are found in neurons or cilia. Not surprisingly, tubulin modification enzymes have been linked to human diseases including cancers and neurodegenerative disorders. We will present our recent work using a combination of X-ray crystallography, small angle X-ray scattering and functional assays to investigate the mechanism of tubulin tyrosine ligase (TTL). TTL catalyzes the ATP-dependent post-translational addition of a tyrosine to the C-terminal end of detyrosinated α-tubulin. The detyrosination/tyrosination cycle regulates recruitment of motors and proteins that track with the growing end of the microtubule. TTL function is essential for neuronal development and reduction in TTL levels is strongly associated with aggressive tumors resistant to chemotherapy. Our first X-ray crystal structure of TTL, defines the structural fold of the TTL-like family of tubulin-modifying enzymes. We show that TTL recognizes tubulin via a dual strategy: it engages the tubulin tail through low-affinity, high-specificity interactions through a conserved positively charged surface, and co-opts what is otherwise a homo-oligomerization interface in structurally related enzymes to form a tight hetero-oligomeric complex with tubulin. TTL forms an elongated complex with the tubulin dimer and prevents incorporation of the dimer into microtubules by capping the tubulin polymerization interface. Interestingly, TTL and stathmin, a ubiquitously expressed tubulin sequestering protein, compete for tubulin binding in vitro and stathmin inhibits tubulin tyrosination. These results suggest that TTL and stathmin have either a partially overlapping footprint on the tubulin dimer or that stathmin induces a tubulin conformation incompatible with stable TTL binding.

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Wöhrl, Birgitta M. "Structural and Functional Aspects of Foamy Virus Protease-Reverse Transcriptase". Viruses 11, n.º 7 (2 de julio de 2019): 598. http://dx.doi.org/10.3390/v11070598.

Texto completo

Resumen

Reverse transcription describes the process of the transformation of single-stranded RNA into double-stranded DNA via an RNA/DNA duplex intermediate, and is catalyzed by the viral enzyme reverse transcriptase (RT). This event is a pivotal step in the life cycle of all retroviruses. In contrast to orthoretroviruses, the domain structure of the mature RT of foamy viruses is different, i.e., it harbors the protease (PR) domain at its N-terminus, thus being a PR-RT. This structural feature has consequences on PR activation, since the enzyme is monomeric in solution and retroviral PRs are only active as dimers. This review focuses on the structural and functional aspects of simian and prototype foamy virus reverse transcription and reverse transcriptase, as well as special features of reverse transcription that deviate from orthoretroviral processes, e.g., PR activation.

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Romero-López, Cristina y Alfredo Berzal-Herranz. "The Role of the RNA-RNA Interactome in the Hepatitis C Virus Life Cycle". International Journal of Molecular Sciences 21, n.º 4 (21 de febrero de 2020): 1479. http://dx.doi.org/10.3390/ijms21041479.

Texto completo

Resumen

RNA virus genomes are multifunctional entities endowed with conserved structural elements that control translation, replication and encapsidation, among other processes. The preservation of these structural RNA elements constraints the genomic sequence variability. The hepatitis C virus (HCV) genome is a positive, single-stranded RNA molecule with numerous conserved structural elements that manage different steps during the infection cycle. Their function is ensured by the association of protein factors, but also by the establishment of complex, active, long-range RNA-RNA interaction networks-the so-called HCV RNA interactome. This review describes the RNA genome functions mediated via RNA-RNA contacts, and revisits some canonical ideas regarding the role of functional high-order structures during the HCV infective cycle. By outlining the roles of long-range RNA-RNA interactions from translation to virion budding, and the functional domains involved, this work provides an overview of the HCV genome as a dynamic device that manages the course of viral infection.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Palencia, Andrés, Thibaut Crépin, Michael T. Vu, Tommie L. Lincecum, Susan A. Martinis y Stephen Cusack. "Structural dynamics of the aminoacylation and proofreading functional cycle of bacterial leucyl-tRNA synthetase". Nature Structural & Molecular Biology 19, n.º 7 (10 de junio de 2012): 677–84. http://dx.doi.org/10.1038/nsmb.2317.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Wehmer, Marc, Till Rudack, Florian Beck, Antje Aufderheide, Günter Pfeifer, Jürgen M. Plitzko, Friedrich Förster, Klaus Schulten, Wolfgang Baumeister y Eri Sakata. "Structural insights into the functional cycle of the ATPase module of the 26S proteasome". Proceedings of the National Academy of Sciences 114, n.º 6 (23 de enero de 2017): 1305–10. http://dx.doi.org/10.1073/pnas.1621129114.

Texto completo

Resumen

In eukaryotic cells, the ubiquitin–proteasome system (UPS) is responsible for the regulated degradation of intracellular proteins. The 26S holocomplex comprises the core particle (CP), where proteolysis takes place, and one or two regulatory particles (RPs). The base of the RP is formed by a heterohexameric AAA+ ATPase module, which unfolds and translocates substrates into the CP. Applying single-particle cryo-electron microscopy (cryo-EM) and image classification to samples in the presence of different nucleotides and nucleotide analogs, we were able to observe four distinct conformational states (s1 to s4). The resolution of the four conformers allowed for the construction of atomic models of the AAA+ ATPase module as it progresses through the functional cycle. In a hitherto unobserved state (s4), the gate controlling access to the CP is open. The structures described in this study allow us to put forward a model for the 26S functional cycle driven by ATP hydrolysis.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

Slesarenko, Natalya A., Anna P. Belyakova y Polina S. Zagorets. "Structural and functional characteristics of ovaries of cattle at different stages of the sexual cycle". Veterinariya, Zootekhniya i Biotekhnologiya 11, n.º 120 (2023): 13–19. http://dx.doi.org/10.36871/vet.zoo.bio.202311002.

Texto completo

Resumen

The article presents the normative micromorphological characteristics of the ovary of a Blackand- White Holstein cow at different stages of the reproductive cycle (proestrus, estrus, metestrus, anestrus). A complex methodological approach was used, including fine anatomical dissection of freshly extracted eviscerated organs, light microscopy of histological sections of the ovary taken within an hour after slaughter from each individual. The patterns of structural and functional transformations of the elements of the ovary (corpus luteum and follicles), which are characteristic of the normal course of the ovarian cycle of a cow, are presented. The results obtained are the reference for diagnosing the condition of the gonads in cows.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

González-Candia, Alejandro, Alejandro A. Candia, Adolfo Paz, Fuad Mobarec, Rodrigo Urbina-Varela, Andrea del Campo, Emilio A. Herrera y Rodrigo L. Castillo. "Cardioprotective Antioxidant and Anti-Inflammatory Mechanisms Induced by Intermittent Hypobaric Hypoxia". Antioxidants 11, n.º 6 (25 de mayo de 2022): 1043. http://dx.doi.org/10.3390/antiox11061043.

Texto completo

Resumen

More than 80 million people live and work (in a chronic or intermittent form) above 2500 masl, and 35 million live in the Andean Mountains. Furthermore, in Chile, it is estimated that 100,000 people work in high-altitude shifts, where stays in the lowlands are interspersed with working visits in the highlands. Acute exposure to high altitude has been shown to induce oxidative stress in healthy human lowlanders due to increased free radical formation and decreased antioxidant capacity. However, intermittent hypoxia (IH) induces preconditioning in animal models, generating cardioprotection. Here, we aim to describe the responses of a cardiac function to four cycles of intermittent hypobaric hypoxia (IHH) in a rat model. The twelve adult Wistar rats were randomly divided into two equal groups, a four-cycle of IHH and a normobaric hypoxic control. Intermittent hypoxia was induced in a hypobaric chamber in four continuous cycles (1 cycle = 4 days of hypoxia + 4 days of normoxia), reaching a barometric pressure equivalent to 4600 m of altitude (428 Torr). At the end of the fourth cycle, cardiac structural and functional variables were also determined by echocardiography; furthermore, cardiac oxidative stress biomarkers (4-Hydroxynonenal, HNE; nitrotyrosine, NT), antioxidant enzymes, and NLRP3 inflammasome panel expression are also determined. Our results show a higher ejection and a shortening fraction of the left ventricle function by the end of the fourth cycle. Furthermore, cardiac tissue presented a decreased expression of antioxidant proteins. However, a decrease in IL-1β, TNF-αn, and oxidative stress markers is observed in IHH compared to normobaric hypoxic controls. Non-significant differences were found in protein levels of NLRP3 and caspase-1. IHH exposure determines structural and functional heart changes. These findings suggest that initial states of IHH are beneficial for cardiovascular function and protection.

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Nicolàs-Aragó, Adrià, Joana Fort, Manuel Palacín y Ekaitz Errasti-Murugarren. "Rush Hour of LATs towards Their Transport Cycle". Membranes 11, n.º 8 (8 de agosto de 2021): 602. http://dx.doi.org/10.3390/membranes11080602.

Texto completo

Resumen

The mammalian SLC7 family comprises the L-amino acid transporters (LATs) and the cationic amino acid transporters (CATs). The relevance of these transporters is highlighted by their involvement in several human pathologies, including inherited rare diseases and acquired diseases, such as cancer. In the last four years, several crystal or cryo-EM structures of LATs and CATs have been solved. These structures have started to fill our knowledge gap that previously was based on the structural biology of remote homologs of the amino acid–polyamine–organocation (APC) transporters. This review recovers this structural and functional information to start generating the molecular bases of the transport cycle of LATs. Special attention is given to the known transporter conformations within the transport cycle and the molecular bases for substrate interaction and translocation, including the asymmetric interaction of substrates at both sides of the plasma membrane.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

He, Dan, Tianjiang Sun, Qiaoran Wang, Tao Ma, Shibing Zheng, Zhanliang Tao y Jing Liang. "Multi-Functional Potassium Ion Assists Ammonium Vanadium Oxide Cathode for High-Performance Aqueous Zinc-Ion Batteries". Batteries 8, n.º 8 (8 de agosto de 2022): 84. http://dx.doi.org/10.3390/batteries8080084.

Texto completo

Resumen

Ammonium vanadium oxide (NH4V4O10) is a promising layered cathode for aqueous zinc-ion batteries owing to its high specific capacity (>300 mA h g−1). However, the structural instability causes serious cycling degradation through irreversible insertion/extraction of NH4+. Herein, a new potassium ammonium vanadate Kx(NH4)1−xV4O10 (named KNVO) is successfully synthesized by a one-step hydrothermal method. The inserted of K+ can act as structural pillars, connect the adjacent layers closer and partially reduce the de-insertion of NH4+. Due to the multi-functional of K+, the prepared KNVO presents a high specific discharge capacity of 432 mA h g−1 at a current density of 0.4 A g−1, long cycle stability (2000 cycles, 94.2%) as well as impressive rate performance (200 mA h g−1 at 8 A g−1).

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Ozaki, Toshinori, Natsumi Kubo y Akira Nakagawara. "p73-Binding Partners and Their Functional Significance". International Journal of Proteomics 2010 (13 de enero de 2010): 1–12. http://dx.doi.org/10.1155/2010/283863.

Texto completo

Resumen

p73 is one of the tumor-suppressor p53 family of nuclear transcription factor. As expected from the structural similarity between p53 and p73, p73 has a tumor-suppressive function. However, p73 was rarely mutated in human primary tumors. Under normal physiological conditions, p73 is kept at an extremely low level to allow cells normal growth. In response to a certain subset of DNA damages, p73 is induced dramatically and transactivates an overlapping set of p53-target genes implicated in the promotion of cell cycle arrest and/or apoptotic cell death. Cells undergo cell cycle arrest and/or apoptotic cell death depending on the type and strength of DNA damages. p73 is regulated largely through the posttranslational modifications such as phosphorylation and acetylation. These chemical modifications are tightly linked to direct protein-protein interactions. In the present paper, the authors describe the functional significance of the protein-protein interactions in the regulation of proapoptotic p73.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Kovalenko, Y. A. y L. M. Chuprinenko. "Structural and functional features of endometrium in patients undergoing in - vitro fertilization". Sechenov Medical Journal 10, n.º 1 (30 de marzo de 2019): 29–34. http://dx.doi.org/10.47093/22187332.2019.1.29-34.

Texto completo

Resumen

A complex of diagnostic and therapeutic measures had been established in order to overcome many diﬀerent causes of female infertility and restore women’s reproductive health.The aim of research is to determine value of immunohistochemical method in determination of disregenerative condition of endometrium in patients undergoing in - vitro fertilization (IVF) program. Materials and methods. The research included 62 patients treated according to IVF program in Clinic of FSBI HPE KSMU NOH Russia, Krasnodar city, in 2017 year. Data of history of disease, laboratory diagnostics, hormonal monitoring at 2-3 day of menstrual cycle and dynamic ultrasound investigation were processed. To evaluate urogenital microbiocenosis real - time PCR was used with “Femoﬂor-16” kit. Pipelle - biopsy of endometrium was taken at 22-24 day of menstrual cycle. Results. After certain investigation patients were divided into three groups. First group consisted of 18 (29.03%) women with primary infertility, second group - 17 (27.42%) patients with secondary infertility, third group - 27 (43.55%) women with recurrent pregnancy loss. Absence of secretory transformation had been revealed in 27.7% women with primary infertility. In patients with secondary infertility and recurrent pregnancy loss proliferative disorders were less frequent, in11.8 and 7.4% respectively. Immunohistochemistry showed that recurrent pregnancy loss was not associated with impairment of both estrogen and progesterone receptors expression, unlike patients with primary and secondary infertility. In patients with recurrent pregnancy loss increased by 2.9 times collagen growth in endometrial stroma was detected. Conclusion. Addition of immunohistochemistry to routine histological investigation allows detection of impaired cyclic endometrial transformations during window of transformation which prevents successful implantation of blastocyst and pregnancy progression.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Wood, Daniel J. y Jane A. Endicott. "Structural insights into the functional diversity of the CDK–cyclin family". Open Biology 8, n.º 9 (septiembre de 2018): 180112. http://dx.doi.org/10.1098/rsob.180112.

Texto completo

Resumen

Since their characterization as conserved modules that regulate progression through the eukaryotic cell cycle, cyclin-dependent protein kinases (CDKs) in higher eukaryotic cells are now also emerging as significant regulators of transcription, metabolism and cell differentiation. The cyclins, though originally characterized as CDK partners, also have CDK-independent roles that include the regulation of DNA damage repair and transcriptional programmes that direct cell differentiation, apoptosis and metabolic flux. This review compares the structures of the members of the CDK and cyclin families determined by X-ray crystallography, and considers what mechanistic insights they provide to guide functional studies and distinguish CDK- and cyclin-specific activities. Aberrant CDK activity is a hallmark of a number of diseases, and structural studies can provide important insights to identify novel routes to therapy.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

Bagnéris, Claire, Claire E. Naylor, Emily C. McCusker y B. A. Wallace. "Structural model of the open–closed–inactivated cycle of prokaryotic voltage-gated sodium channels". Journal of General Physiology 145, n.º 1 (15 de diciembre de 2014): 5–16. http://dx.doi.org/10.1085/jgp.201411242.

Texto completo

Resumen

In excitable cells, the initiation of the action potential results from the opening of voltage-gated sodium channels. These channels undergo a series of conformational changes between open, closed, and inactivated states. Many models have been proposed for the structural transitions that result in these different functional states. Here, we compare the crystal structures of prokaryotic sodium channels captured in the different conformational forms and use them as the basis for examining molecular models for the activation, slow inactivation, and recovery processes. We compare structural similarities and differences in the pore domains, specifically in the transmembrane helices, the constrictions within the pore cavity, the activation gate at the cytoplasmic end of the last transmembrane helix, the C-terminal domain, and the selectivity filter. We discuss the observed differences in the context of previous models for opening, closing, and inactivation, and present a new structure-based model for the functional transitions. Our proposed prokaryotic channel activation mechanism is then compared with the activation transition in eukaryotic sodium channels.

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Mas, Guillaume, Jia-Ying Guan, Elodie Crublet, Elisa Colas Debled, Christine Moriscot, Pierre Gans, Guy Schoehn, Pavel Macek, Paul Schanda y Jerome Boisbouvier. "Structural investigation of a chaperonin in action reveals how nucleotide binding regulates the functional cycle". Science Advances 4, n.º 9 (septiembre de 2018): eaau4196. http://dx.doi.org/10.1126/sciadv.aau4196.

Texto completo

Resumen

Chaperonins are ubiquitous protein assemblies present in bacteria, eukaryota, and archaea, facilitating the folding of proteins, preventing protein aggregation, and thus participating in maintaining protein homeostasis in the cell. During their functional cycle, they bind unfolded client proteins inside their double ring structure and promote protein folding by closing the ring chamber in an adenosine 5′-triphosphate (ATP)–dependent manner. Although the static structures of fully open and closed forms of chaperonins were solved by x-ray crystallography or electron microscopy, elucidating the mechanisms of such ATP-driven molecular events requires studying the proteins at the structural level under working conditions. We introduce an approach that combines site-specific nuclear magnetic resonance observation of very large proteins, enabled by advanced isotope labeling methods, with an in situ ATP regeneration system. Using this method, we provide functional insight into the 1-MDa large hsp60 chaperonin while processing client proteins and reveal how nucleotide binding, hydrolysis, and release control switching between closed and open states. While the open conformation stabilizes the unfolded state of client proteins, the internalization of the client protein inside the chaperonin cavity speeds up its functional cycle. This approach opens new perspectives to study structures and mechanisms of various ATP-driven biological machineries in the heat of action.

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Kapoor, Karan, Sundar Thangapandian y Emad Tajkhorshid. "Extended-ensemble docking to probe dynamic variation of ligand binding sites during large-scale structural changes of proteins". Chemical Science 13, n.º 14 (2022): 4150–69. http://dx.doi.org/10.1039/d2sc00841f.

Texto completo

Resumen

Functional states of P-glycoprotein formed during its full transition cycle (red to blue), captured by molecular dynamics simulations, form a structural framework for extended-ensemble docking of small-molecule ligands of diverse activities.

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Riedl, Mareike, Annika Strauch, Dragana A. M. Catici y Martin Haslbeck. "Proteinaceous Transformers: Structural and Functional Variability of Human sHsps". International Journal of Molecular Sciences 21, n.º 15 (30 de julio de 2020): 5448. http://dx.doi.org/10.3390/ijms21155448.

Texto completo

Resumen

The proteostasis network allows organisms to support and regulate the life cycle of proteins. Especially regarding stress, molecular chaperones represent the main players within this network. Small heat shock proteins (sHsps) are a diverse family of ATP-independent molecular chaperones acting as the first line of defense in many stress situations. Thereby, the promiscuous interaction of sHsps with substrate proteins results in complexes from which the substrates can be refolded by ATP-dependent chaperones. Particularly in vertebrates, sHsps are linked to a broad variety of diseases and are needed to maintain the refractive index of the eye lens. A striking key characteristic of sHsps is their existence in ensembles of oligomers with varying numbers of subunits. The respective dynamics of these molecules allow the exchange of subunits and the formation of hetero-oligomers. Additionally, these dynamics are closely linked to the chaperone activity of sHsps. In current models a shift in the equilibrium of the sHsp ensemble allows regulation of the chaperone activity, whereby smaller oligomers are commonly the more active species. Different triggers reversibly change the oligomer equilibrium and regulate the activity of sHsps. However, a finite availability of high-resolution structures of sHsps still limits a detailed mechanistic understanding of their dynamics and the correlating recognition of substrate proteins. Here we summarize recent advances in understanding the structural and functional relationships of human sHsps with a focus on the eye-lens αA- and αB-crystallins.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Livesay, S. Brent, Scott E. Collier, Danny A. Bitton, Jürg Bähler y Melanie D. Ohi. "Structural and Functional Characterization of the N Terminus of Schizosaccharomyces pombe Cwf10". Eukaryotic Cell 12, n.º 11 (6 de septiembre de 2013): 1472–89. http://dx.doi.org/10.1128/ec.00140-13.

Texto completo

Resumen

ABSTRACT The spliceosome is a dynamic macromolecular machine that catalyzes the removal of introns from pre-mRNA, yielding mature message. Schizosaccharomyces pombe Cwf10 (homolog of Saccharomyces cerevisiae Snu114 and human U5-116K), an integral member of the U5 snRNP, is a GTPase that has multiple roles within the splicing cycle. Cwf10/Snu114 family members are highly homologous to eukaryotic translation elongation factor EF2, and they contain a conserved N-terminal extension (NTE) to the EF2-like portion, predicted to be an intrinsically unfolded domain. Using S. pombe as a model system, we show that the NTE is not essential, but cells lacking this domain are defective in pre-mRNA splicing. Genetic interactions between cwf10 -Δ NTE and other pre-mRNA splicing mutants are consistent with a role for the NTE in spliceosome activation and second-step catalysis. Characterization of Cwf10-NTE by various biophysical techniques shows that in solution the NTE contains regions of both structure and disorder. The first 23 highly conserved amino acids of the NTE are essential for its role in splicing but when overexpressed are not sufficient to restore pre-mRNA splicing to wild-type levels in cwf10 -Δ NTE cells. When the entire NTE is overexpressed in the cwf10 -Δ NTE background, it can complement the truncated Cwf10 protein in trans , and it immunoprecipitates a complex similar in composition to the late-stage U5.U2/U6 spliceosome. These data show that the structurally flexible NTE is capable of independently incorporating into the spliceosome and improving splicing function, possibly indicating a role for the NTE in stabilizing conformational rearrangements during a splice cycle.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Sugino, Kazuyuki y Hans Machemer. "The ciliary cycle during hyperpolarization-induced activity: An analysis of axonemal functional parameters". Cell Motility and the Cytoskeleton 11, n.º 4 (1988): 275–90. http://dx.doi.org/10.1002/cm.970110406.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Chen, Yue, Xiaobing Wang, Xiaoli Wang, Tong Cheng, Kuankuan Fu, Zhentian Qin y Ke Feng. "Biofilm Structural and Functional Features on Microplastic Surfaces in Greenhouse Agricultural Soil". Sustainability 14, n.º 12 (8 de junio de 2022): 7024. http://dx.doi.org/10.3390/su14127024.

Texto completo

Resumen

Microplastics (MPs) enter the soil through a variety of pathways, including plastic mulching, sludge, and organic manure application. In recent years, domestic and foreign experts and scholars have been concerned about the residues and contamination of MPs in the soil of greenhouse agriculture. In this investigation, five types of MPs including low-density polyethylene (LDPE), high-density polyethylene (HDPE), polystyrene (PS), polypropylene (PP), and polyethylene terephthalate (PET), and two concentrations (1% and 5%, w/w) were used in a 30-day external exposure test. Evidence of microbial enrichment was found on the surface of the MPs. The total amount of biofilm on the surface of MPs increased dramatically with increasing exposure time and MP concentrations. The polysaccharide content of extracellular polymers (EPS) in biofilms was significantly different, and the maximum PS1 (1% (w/w) PS) concentration was 50.17 mg/L. However, EPS protein content did not change significantly. The dominant bacteria on the surface of MPs with different types and concentrations were specific, and the relative abundance of Patescibacteria was significantly changed at the phylum level. At the genus level, Methylophaga, Saccharimonadales, and Sphingomonas dominated the flora of LDPE1 (1% (w/w) LDPE), PS1, and PET5 (5% (w/w) PET). The dominant bacteria decompose organic materials and biodegrade organic contaminants. According to the FAPROTAX functional prediction study, chemoheterotrophy and aerobic chemoheterotrophyplay a role in ecosystem processes such as carbon cycle and climate regulation. The application of LDPE1 has a greater impact on the carbon cycle. Plant development and soil nutrients in greenhouse agriculture may be influenced by the interaction between MPs and microorganisms in the growing area, while MP biofilms have an impact on the surrounding environment and pose an ecological hazard.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Verschuren, Emmy W., Nic Jones y Gerard I. Evan. "The cell cycle and how it is steered by Kaposi's sarcoma-associated herpesvirus cyclin". Journal of General Virology 85, n.º 6 (1 de junio de 2004): 1347–61. http://dx.doi.org/10.1099/vir.0.79812-0.

Texto completo

Resumen

A timely coordination of cellular DNA synthesis and division cycles is governed by the temporal and spatial activation of cyclin-dependent kinases (Cdks). The primary regulation of Cdk activation is through binding to partner cyclin proteins. Several gammaherpesviruses encode a viral homologue of cellular cyclin D, which may function to deregulate host cell cycle progression. One of these is encoded by Kaposi's sarcoma-associated herpesvirus (KSHV) and is called K cyclin or viral cyclin (v-cyclin). v-Cyclin is expressed in most of the malignant cells that are associated with KSHV infection in humans, labelling v-cyclin as a putative viral oncogene. Here are described some of the major structural and functional properties of mammalian cyclin/Cdk complexes, some of which are phenocopied by v-cyclin. In addition, the molecular events leading to orderly progression through the G1/S and G/M cell cycle phases are reviewed. This molecular picture serves as a platform on which to explain v-cyclin-specific functional properties. Interesting but largely speculative issues concern the interplay between v-cyclin-mediated cell cycle deregulation and molecular progression of KSHV-associated neoplasms.

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Haydar, A. y Maksim Zheleznov. "Method of using georadiolocation to control the serviceability of structures during their life cycle". Construction and Architecture 11, n.º 1 (24 de marzo de 2023): 9. http://dx.doi.org/10.29039/2308-0191-2022-11-1-9-9.

Texto completo

Resumen

Advances in structural health monitoring are helping professionals identify potential building hazards caused by aging and other environmental factors. Monitoring the state of structures primarily allows you to examine the current state of structural systems to assess their functional suitability and performance level. If the assessment of the condition of the structure reveals a lower level of performance than required, then work should be carried out immediately to restore and reconstruct it. , and specialists who monitor the state of "health" of buildings.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Avelar, Lívia G. A., Laila A. Nahum, Luiza F. Andrade y Guilherme Oliveira. "Functional Diversity of the Schistosoma mansoni Tyrosine Kinases". Journal of Signal Transduction 2011 (15 de junio de 2011): 1–11. http://dx.doi.org/10.1155/2011/603290.

Texto completo

Resumen

Schistosoma mansoni, one of the causative agents of schistosomiasis, has a complex life cycle infecting over 200 million people worldwide. Such a successful and prolific parasite life cycle has been shown to be dependent on the adaptive interaction between the parasite and hosts. Tyrosine kinases (TKs) play a key role in signaling pathways as demonstrated by a large body of experimental work in eukaryotes. Furthermore, comparative genomics have allowed the identification of TK homologs and provided insights into the functional role of TKs in several biological systems. Finally, TK structural biology has provided a rational basis for obtaining selective inhibitors directed to the treatment of human diseases. This paper covers the important aspects of the phospho-tyrosine signaling network in S. mansoni, Caenorhabditis elegans, and humans, the main process of functional diversification of TKs, that is, protein-domain shuffling, and also discusses TKs as targets for the development of new anti-schistosome drugs.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Skok, James E. "Policy Issue Networks and the Public Policy Cycle: A Structural-Functional Framework for Public Administration". Public Administration Review 55, n.º 4 (julio de 1995): 325. http://dx.doi.org/10.2307/977123.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Abed, Raeid M. M., Dirk de Beer y Peter Stief. "Functional-Structural Analysis of Nitrogen-Cycle Bacteria in a Hypersaline Mat from the Omani Desert". Geomicrobiology Journal 32, n.º 2 (10 de diciembre de 2014): 119–29. http://dx.doi.org/10.1080/01490451.2014.932033.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Albury, Mary S., Catherine Elliott, Yasutoshi Kido, Kiyoshi Kita y Anthony L. Moore. "Structural and functional characterisation of alternative oxidases: Role of conserved tyrosines in the catalytic cycle". Biochimica et Biophysica Acta (BBA) - Bioenergetics 1797 (julio de 2010): 92. http://dx.doi.org/10.1016/j.bbabio.2010.04.279.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "Functional and Structural cycle"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros