Long-range structural changes in proteinase K triggered by calcium ion removal

Nature ◽  
1989 ◽  
Vol 337 (6206) ◽  
pp. 481-484 ◽  
Author(s):  
Jürgen Bajorath ◽  
Srinivasan Raghunathan ◽  
Winfried Hinrichs ◽  
Wolfram Saenger
Keyword(s):  
Long Range ◽  
Calcium Ion ◽  
Structural Changes ◽  
Proteinase K ◽  
Ion Removal

scholarly journals Structural Changes in the Acceptor Site of Photosystem II upon Ca2+/Sr2+ Exchange in the Mn4CaO5 Cluster Site and the Possible Long-Range Interactions

Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 371
Author(s):  
Koua
Keyword(s):  
Crystal Structure ◽  
Photosystem Ii ◽  
Long Range ◽  
Electron Acceptor ◽  
Structural Changes ◽  
Acceptor Site ◽  
Oxygen Evolving Complex ◽  
Long Range Interactions ◽  
Structural Perturbations ◽  
Oxygen Evolving

The Mn4CaO5 cluster site in the oxygen-evolving complex (OEC) of photosystem II (PSII) undergoes structural perturbations, such as those induced by Ca2+/Sr2+ exchanges or Ca/Mn removal. These changes have been known to induce long-range positive shifts (between +30 and +150 mV) in the redox potential of the primary quinone electron acceptor plastoquinone A (QA), which is located 40 Å from the OEC. To further investigate these effects, we reanalyzed the crystal structure of Sr-PSII resolved at 2.1 Å and compared it with the native Ca-PSII resolved at 1.9 Å. Here, we focus on the acceptor site and report the possible long-range interactions between the donor, Mn4Ca(Sr)O5 cluster, and acceptor sites.

scholarly journals Calcium-Ion Removal from Peat by a Mechanical Filter Cake Washing Process

2007 ◽  
Vol 30 (8) ◽  
pp. 1055-1061 ◽  
Author(s):  
F. Ruslim ◽  
H. Nirschl ◽  
A. Mezhibor ◽  
L. Rikhvanov
Keyword(s):  
Calcium Ion ◽  
Filter Cake ◽  
Ion Removal ◽  
Washing Process ◽  
Mechanical Filter

Structural changes from polyimide films to graphite: Part IV. Novax and PPT

1995 ◽  
Vol 10 (4) ◽  
pp. 1024-1027 ◽  
Author(s):  
C. Bourgerette ◽  
A. Oberlin ◽  
M. Inagaki
Keyword(s):  
Long Range ◽  
Structural Changes ◽  
Film Plane ◽  
High Rank ◽  
Polyimide Films ◽  
Electron Microscopies ◽  
Higher Temperature ◽  
Cross Linker ◽  
Graphite Part

Various polyimide films (Kapton, Upilex, Novax, and PPT) were carbonized and graphitized up to 3000 °C. They were studied by optical and electron microscopies. All films retaining oxygen as a cross linker over 1000 °C, i.e., Kapton, Upilex, and Novax, graphitize as anthracites (high rank coals) do. They get a long range statistical orientation parallel to the film plane with a nanotexture of flattened pores. Graphitization is both sudden and perfect above 2100 °C when the pore walls break. Since oxygen is released at 1000 °C, the film PPT behaves as a compact nonporous graphitizing carbon (orientation parallel to the film plane). Thermal graphitization is progressive and begins at a higher temperature.

scholarly journals Correlation between long range and local structural changes in Ni-rich layered materials during charge and discharge process

2019 ◽  
Vol 412 ◽  
pp. 336-343 ◽  
Author(s):  
Shiyao Zheng ◽  
Chaoyu Hong ◽  
Xiaoyun Guan ◽  
Yuxuan Xiang ◽  
Xiangsi Liu ◽  
...  
Keyword(s):  
Long Range ◽  
Structural Changes ◽  
Layered Materials ◽  
Discharge Process

Competitive calcium ion binding to end-tethered weak polyelectrolytes

Soft Matter ◽  
2018 ◽  
Vol 14 (12) ◽  
pp. 2365-2378 ◽  
Author(s):  
Rikkert J. Nap ◽  
Sung Hyun Park ◽  
Igal Szleifer
Keyword(s):  
Calcium Ion ◽  
Structural Changes ◽  
Molecular Model ◽  
Ion Concentration ◽  
Ion Binding ◽  
Spherical Nanoparticles ◽  
Planar Surfaces ◽  
Calcium Ion Binding ◽  
Weak Polyelectrolytes

We have developed a molecular model to describe the structural changes and potential collapse of weak polyelectrolyte layers end-tethered to planar surfaces and spherical nanoparticles as a function of pH and divalent ion concentration.

scholarly journals Long-Range Structural Changes in the Meiotic Nucleus Revealed by Changes in Stress Communication Along the Chromosome

2018 ◽  
Vol 114 (3) ◽  
pp. 30a
Author(s):  
Trent Newman ◽  
Bruno G. Beltran ◽  
James McGehee ◽  
Cori Cahoon ◽  
Daniel Elnatan ◽  
...  
Keyword(s):  
Long Range ◽  
Structural Changes

scholarly journals Mediator facilitates transcriptional activation and dynamic long-range contacts at the IgH locus during class switch recombination

2016 ◽  
Vol 213 (3) ◽  
pp. 303-312 ◽  
Author(s):  
Anne-Sophie Thomas-Claudepierre ◽  
Isabelle Robert ◽  
Pedro P. Rocha ◽  
Ramya Raviram ◽  
Ebe Schiavo ◽  
...  
Keyword(s):  
B Cells ◽  
Long Range ◽  
Transcriptional Activation ◽  
Transcription Initiation ◽  
Structural Changes ◽  
Class Switch Recombination ◽  
Mediator Complex ◽  
Loop Formation ◽  
Class Switch ◽  
Igh Locus

Immunoglobulin (Ig) class switch recombination (CSR) is initiated by the transcription-coupled recruitment of activation-induced cytidine deaminase (AID) to Ig switch regions (S regions). During CSR, the IgH locus undergoes dynamic three-dimensional structural changes in which promoters, enhancers, and S regions are brought to close proximity. Nevertheless, little is known about the underlying mechanisms. In this study, we show that Med1 and Med12, two subunits of the mediator complex implicated in transcription initiation and long-range enhancer/promoter loop formation, are dynamically recruited to the IgH locus enhancers and the acceptor regions during CSR and that their knockdown in CH12 cells results in impaired CSR. Furthermore, we show that conditional inactivation of Med1 in B cells results in defective CSR and reduced acceptor S region transcription. Finally, we show that in B cells undergoing CSR, the dynamic long-range contacts between the IgH enhancers and the acceptor regions correlate with Med1 and Med12 binding and that they happen at a reduced frequency in Med1-deficient B cells. Our results implicate the mediator complex in the mechanism of CSR and are consistent with a model in which mediator facilitates the long-range contacts between S regions and the IgH locus enhancers during CSR and their transcriptional activation.

Role of LHCII-containing macrodomains in the structure, function and dynamics of grana

2000 ◽  
Vol 27 (3) ◽  
pp. 279 ◽  
Author(s):  
G. Garab ◽  
L. Mustárdy
Keyword(s):  
Excitation Energy ◽  
Long Range ◽  
Structural Changes ◽  
Higher Plants ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Lateral Heterogeneity ◽  
Long Distance ◽  
3D Network

In higher plants and green algae two types of thylakoids are distinguished, granum (stacked) and stroma (unstacked) thylakoids. They form a three-dimensional (3D) network with large lateral heterogeneity: photosystem II (PSII) and the associated main chlorophyll a/b light-harvesting complex (LHCII) are found predominantly in the stacked region, while PSI and LHCI are located mainly in the unstacked region of the membrane. This picture emerged from the discovery of the physical separation of the two photosystems (Boardman and Anderson 1964). Granal chloroplasts possess significant flexibility, which is essential for optimizing the photosynthetic machinery under various environmental conditions. However, our understanding concerning the assembly, structural dynamics and regulatory functions of grana is far from being complete. In this paper we overview the significance of the three-dimensional structure of grana in the absorption properties, ionic equilibrations, and in the diffusion of membrane components between the stacked and unstacked regions. Further, we discuss the role of chiral macrodomains in the grana. Lateral heterogeneity of thylakoid membranes is proposed to be a consequence of the formation of macrodomains constituted of LHCII and PSII; their long range order permits long distance migration of excitation energy, which explains the energetic connectivity of PSII particles. The ability of macrodomains to undergo light-induced reversible structural changes lends structural flexibility to the granum. In purified LHCII, which has also been shown to form stacked lamellar aggregates with long range chiral order, excitation energy migrates for large distances; these macroaggregates are also capable of undergoing light-induced reversible structural changes and fluorescence quenching. Hence, some basic properties of grana appear to originate from its main constituent, the LHCII.

Sodium-Modified Vermiculite for Calcium Ion Removal from Aqueous Solution

2019 ◽  
Vol 58 (22) ◽  
pp. 9380-9389
Author(s):  
Roberto R. C. Lima ◽  
Paulo Douglas S. de Lima ◽  
Vitor Rodrigues Greati ◽  
Paulla B. F. de Sousa ◽  
Gabriel V. S. Medeiros
Keyword(s):  
Aqueous Solution ◽  
Calcium Ion ◽  
Ion Removal
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