Involvement of nitrogen functional groups in high-affinity copper binding in tomato and wheat root apoplasts: spectroscopic and thermodynamic evidence

Metallomics ◽  
2016 ◽  
Vol 8 (3) ◽  
pp. 366-376 ◽  
Author(s):  
Stéphanie Guigues ◽  
Matthieu N. Bravin ◽  
Cédric Garnier ◽  
Armand Masion ◽  
Claire Chevassus-Rosset ◽  
...  
Keyword(s):  
Functional Groups ◽  
Local Environment ◽  
Wheat Root ◽  
Copper Binding ◽  
High Affinity

A dual local environment of Cu in root apoplasts was identified.

XAFS study of the high-affinity copper-binding site of human PrP 91–231 and its low-resolution structure in solution 1 1Edited by I. A. Wilson

2001 ◽  
Vol 311 (3) ◽  
pp. 467-473 ◽  
Author(s):  
S.Samar Hasnain ◽  
Loretta M. Murphy ◽  
Richard W. Strange ◽  
J.Günter Grossmann ◽  
Anthony R. Clarke ◽  
...  
Keyword(s):  
Binding Site ◽  
Copper Binding ◽  
Low Resolution ◽  
High Affinity ◽  
Structure In Solution ◽  
Resolution Structure

scholarly journals High affinity copper binding by stefin B (cystatin B) and its role in the inhibition of amyloid fibrillation

FEBS Journal ◽  
2006 ◽  
Vol 273 (18) ◽  
pp. 4250-4263 ◽  
Author(s):  
Eva Žerovnik ◽  
Katja Škerget ◽  
Magda Tušek-Žnidarič ◽  
Corina Loeschner ◽  
Marcus W. Brazier ◽  
...  
Keyword(s):  
Copper Binding ◽  
Cystatin B ◽  
High Affinity ◽  
Amyloid Fibrillation

Identification of a novel high affinity copper binding site in the APP(145–155) fragment of amyloid precursor protein

2004 ◽  
pp. 16-22 ◽  
Author(s):  
Daniela Valensin ◽  
Francesca Maria Mancini ◽  
Marek Łuczkowski ◽  
Anna Janicka ◽  
Kornelia Wiśniewska ◽  
...  
Keyword(s):  
Amyloid Precursor Protein ◽  
Binding Site ◽  
Precursor Protein ◽  
Copper Binding ◽  
High Affinity

A Functional Role for Aβ in Metal Homeostasis? N-Truncation and High-Affinity Copper Binding

2015 ◽  
Vol 127 (36) ◽  
pp. 10606-10610 ◽  
Author(s):  
Mariusz Mital ◽  
Nina E. Wezynfeld ◽  
Tomasz Frączyk ◽  
Magdalena Z. Wiloch ◽  
Urszula E. Wawrzyniak ◽  
...  
Keyword(s):  
Functional Role ◽  
Metal Homeostasis ◽  
Copper Binding ◽  
High Affinity

scholarly journals Sheathless Mutant of Cyanobacterium Gloeothece sp. Strain PCC 6909 with Increased Capacity To Remove Copper Ions from Aqueous Solutions

2008 ◽  
Vol 74 (9) ◽  
pp. 2797-2804 ◽  
Author(s):  
Ernesto Micheletti ◽  
Sara Pereira ◽  
Francesca Mannelli ◽  
Pedro Moradas-Ferreira ◽  
Paula Tamagnini ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Functional Groups ◽  
Metal Removal ◽  
Copper Ions ◽  
Dry Weight ◽  
Copper Binding ◽  
Wild Type ◽  
Removal Capacity ◽  
Acidic Sugars

ABSTRACT The cyanobacterium Gloeothece sp. strain PCC 6909 and its sheathless mutant were tested for their abilities to remove copper ions from aqueous solutions, with the aim of defining the role of the various outermost polysaccharidic investments in the removal of the metal ions. Microscopy studies and chemical analyses revealed that, although the mutant does not possess a sheath, it releases large amounts of polysaccharidic material (released exocellular polysaccharides [RPS]) into the culture medium. The RPS of the wild type and the mutant are composed of the same 11 sugars, although they are present in different amounts, and the RPS of the mutant possesses a larger amount of acidic sugars and a smaller amount of deoxysugars than the wild type. Unexpectedly, whole cultures of the mutant were more effective in the removal of the heavy metal than the wild type (46.3 ± 3.1 and 26.7 ± 1.5 mg of Cu2+ removed per g of dry weight, respectively). Moreover, we demonstrated that the contribution of the sheath to the metal-removal capacity of the wild type is scarce and that the RPS of the mutant is more efficient in removing copper. This suggests that the metal ions are preferably bound to the cell wall and to RPS functional groups rather than to the sheath. Therefore, the increased copper binding efficiency observed with the sheathless mutant can be attributed to the release of a polysaccharide containing larger amounts and/or more accessible functional groups (e.g., carboxyl and amide groups).

scholarly journals Iodination of Calsequestrin in the Sarcoplasmic Reticulum of Rabbit Skeletal Muscle: A Re-Examination

1979 ◽  
Vol 32 (2) ◽  
pp. 177 ◽  
Author(s):  
Ronald K Tume
Keyword(s):  
Skeletal Muscle ◽  
Molecular Weight ◽  
Sarcoplasmic Reticulum ◽  
Atpase Activity ◽  
Calcium Binding ◽  
Local Environment ◽  
Maximal Inhibition ◽  
High Affinity ◽  
Tris Maleate ◽  
Sepharose 4B

The exposed proteins of sarcoplasmic reticulum (SR) vesicles from skeletal muscle were iodinated with the use of Sepharose 4B-bound lactoperoxidase, so that the location of the proteins in the membrane could be determined. It was found that the pattern of protein labelling could be modified simply by changing the constituents of the incubation media. This implies that the position or configuration of a particular protein in the membrane can be altered by the local environment. When the reaction was performed in the presence of 25 mM tris-maleate, pH 7 �0, alone, the Ca2+ pump ATPase (molecular weight 105000) and calsequestrin (47000) were both heavily labelled, suggesting they are at least partially exposed on the outer surface of the membrane. By contrast the high affinity calcium-binding protein (55000) was not labelled. However, when the vesicles were iodinated under conditions that were suitable for ATPase activity and Ca2+ accumulation, namely in the presence of 25 mM tris-maleate, pH 7 �0, 5 mM ATP, 5 mM Mg2+ and 0�05 mM Ca2+, a different pattern of labelling was obtained. No labelling of calsequestrin was observed whereas the extent of labelling of the Ca2+ pump ATPase remained about the same. The inclusion of anyone of the additives mentioned was effective in inhibiting the iodination of calsequestrin in the SR vesicle. When added alone, Ca2+ was more effective than Mg2+ in preventing labelling of calsequestrin. Half-maximal inhibition was observed at concentrations of approximately 0�05 mM Ca 2+ and 0�2-0�3 mM Mg2+ . Although much reduced, significant labelling of calsequestrin was observed even in the presence of 5 mM ATP. Investigations with partially purified calsequestrin revealed that the iodination of calsequestrin was the same in both the presence and absence of 1 mM Ca2 +. Therefore the reduction in label observed in intact SR vesicles probably represents a change in the location of calsequestrin within the membrane, rather than inhibition by Ca2+ of the iodination sites of the protein itself.

scholarly journals Agarose Hydrogels Enriched by Humic Acids as the Complexation Agent

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 687 ◽  
Author(s):  
Martina Klučáková
Keyword(s):  
Methylene Blue ◽  
Humic Substances ◽  
Functional Groups ◽  
Humic Acids ◽  
Diffusion Coefficients ◽  
Rhodamine 6G ◽  
Effective Diffusion ◽  
High Affinity ◽  
Effective Diffusion Coefficients ◽  
Complexation Agent

The transport properties of agarose hydrogels enriched by humic acids were studied. Methylene blue, rhodamine 6G and Cu(II) ions were incorporated into hydrogel as diffusion probes, and then their release into water was monitored. Cu(II) ions as well as both the dyes studied in this work have high affinity to humic substances and their interactions strongly affected their diffusion in hydrogels. It was confirmed that humic acids retarded the transport of diffusion probes. Humic acids’ enrichment caused the decrease in the values of effective diffusion coefficients due to their complexation with diffusion probes. In general, the diffusion of dyes was more affected by the complexation with humic acids in comparison with Cu(II) ions. The effect of complexation was selective for the particular diffusion probe. The strongest effect was obtained for the diffusion of methylene blue. It was assumed that metal ions interacted preferentially with acidic functional groups. In contrast to Cu(II) ions, dyes can interact with acidic functional groups, and the condensed cyclic structures of the dye probes supported their interactions with the hydrophobic domains of humic substances.

scholarly journals Alkali cation selectivity of the wheat root high-affinity potassium transporter HKT1

1996 ◽  
Vol 10 (5) ◽  
pp. 869-882 ◽  
Author(s):  
Walter Gassmann ◽  
Francisco Rubio ◽  
Julian I. Schroeder
Keyword(s):  
Wheat Root ◽  
Alkali Cation ◽  
Potassium Transporter ◽  
Cation Selectivity ◽  
High Affinity

TaPht1;4, a high-affinity phosphate transporter gene in wheat (Triticum aestivum), plays an important role in plant phosphate acquisition under phosphorus deprivation

2013 ◽  
Vol 40 (4) ◽  
pp. 329 ◽  
Author(s):  
Xiaoman Liu ◽  
Xiaolei Zhao ◽  
Lijun Zhang ◽  
Wenjing Lu ◽  
Xiaojuan Li ◽  
...  
Keyword(s):  
Expressed Sequence Tag ◽  
Growth Traits ◽  
Brachypodium Distachyon ◽  
Critical Role ◽  
Wheat Root ◽  
Phosphate Transporter ◽  
Wild Type Plant ◽  
Night Time ◽  
High Affinity ◽  
Membrane Spanning

An expressed sequence tag (EST) highly similar to BdPT1–4, a phosphate transporter (PT) gene in Brachypodium distachyon, was obtained in a wheat root cDNA subtractive suppression library containing genes that respond to low-phosphate (Pi) stress. The DNA sequence covering this EST (designated as TaPht1;4) was determined based on screening a wheat DNA library. TaPht1;4 consists of two exons and one intron and encodes a 555 amino acid (aa) polypeptide with a molecular weight of 60.85 kDa and an isoelectric point of 7.60. TaPht1;4 contains 12 conserved membrane-spanning domains similar to previously reported PTs in diverse plant species. Yeast complement analysis in low-Pi medium confirmed that TaPht1;4 confers the capacity to uptake Pi to MB192, a yeast strain with a defective high-affinity PT; with an apparent Km of 35.3 μM. The TaPht1;4 transcripts were specifically detected in the root and were highly induced under Pi deficiency. TaPht1;4 was also expressed following a diurnal pattern, i.e. high levels during daytime and low levels during night-time. TaPht1;4 overexpression and downregulation dramatically altered the plant phenotypic features under low-Pi conditions. Samples that overexpressed TaPht1;4 had significantly improved growth traits and accumulated more Pi than the wild-type plant and those with downregulated TaPht1;4 expression. Therefore, TaPht1;4 is a high-affinity PT gene that plays a critical role in wheat Pi acquisition under Pi deprivation.

Structure of the flavocytochrome c sulfide dehydrogenase associated with the copper-binding protein CopC from the haloalkaliphilic sulfur-oxidizing bacterium Thioalkalivibrio paradoxusARh 1

2018 ◽  
Vol 74 (7) ◽  
pp. 632-642 ◽  
Author(s):  
Eugeny M. Osipov ◽  
Anastasia V. Lilina ◽  
Stanislav I. Tsallagov ◽  
Tatyana N. Safonova ◽  
Dimitry Y. Sorokin ◽  
...  
Keyword(s):  
Binding Protein ◽  
Copper Ion ◽  
Copper Binding ◽  
X Ray Diffraction ◽  
High Affinity ◽  
Key Factor ◽  
Copper Binding Protein ◽  
Α Helix ◽  
Flavin Binding ◽  
Binding Subunit

Flavocytochrome c sulfide dehydrogenase from Thioalkalivibrio paradoxus (TpFCC) is a heterodimeric protein consisting of flavin- and monohaem c-binding subunits. TpFCC was co-purified and co-crystallized with the dimeric copper-binding protein TpCopC. The structure of the TpFCC–(TpCopC)2 complex was determined by X-ray diffraction at 2.6 Å resolution. The flavin-binding subunit of TpFCC is structurally similar to those determined previously, and the structure of the haem-binding subunit is similar to that of the N-terminal domain of dihaem FCCs. According to classification based on amino-acid sequence, TpCopC belongs to a high-affinity CopC subfamily characterized by the presence of a conserved His1-Xxx-His3 motif at the N-terminus. Apparently, a unique α-helix which is present in each monomer of TpCopC at the interface with TpFCC plays a key role in complex formation. The structure of the copper-binding site in TpCopC is similar to those in other known CopC structures. His3 is not involved in binding to the copper ion and is 6–7 Å away from this ion. Therefore, the His1-Xxx-His3 motif cannot be considered to be a key factor in the high affinity of CopC for copper(II) ions. It is suggested that the TpFCC–(TpCopC)2 heterotetramer may be a component of a large periplasmic complex that is responsible for thiocyanate metabolism.

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