Subcellular Distribution of Inorganic Phosphate, and Levels of Nucleoside Triphosphate, in Mature Maize Roots at Low External Phosphate Concentrations: Measurements with31P-NMR

1993 ◽  
Vol 44 (3) ◽  
pp. 587-598 ◽  
Author(s):  
R B. LEE ◽  
R. G. RATCLIFFE
Keyword(s):  
Subcellular Distribution ◽  
Inorganic Phosphate ◽  
Nucleoside Triphosphate ◽  
Maize Roots

The role of nucleoside triphosphate hydrolysis in transducing systems: p21ras and muscle

1992 ◽  
Vol 336 (1276) ◽  
pp. 19-24 ◽  
Keyword(s):  
Protein Interactions ◽  
Inorganic Phosphate ◽  
Signal Transduction Pathway ◽  
Basic Mechanism ◽  
Nucleoside Triphosphate ◽  
Protein Protein Interactions ◽  
Phosphate Release ◽  
Kinetics Of ◽  
Degree Of Similarity

A variety of systems use nucleoside triphosphate hydrolysis to control or provide energy for biological processes, mediated through protein-protein interactions. The nature of this coupling may vary, but often there is a degree of similarity. In this paper, two systems are compared: actomyosin in muscle and p21ras in a signal transduction pathway as yet undefined. The mechanism of the nucleotide triphosphate hydrolysis and the consequent changes in the protein-nucleotide complex have been investigated, to understand how the coupling to biological function is achieved. The basal nucleoside triphosphatase mechanisms are compared and the roles of proteins that activate the hydrolysis, actin and GAP, are discussed. The cleavage process was probed by stereochemical techniques to determine the basic mechanism, of either a phosphorylated enzyme intermediate or direct displacement of nucleoside diphosphate by water. Phosphate-water oxygen exchange probes were used to investigate nucleoside triphosphate and inorganic phosphate release steps. A new method of probing the kinetics of inorganic phosphate release directly has been developed. In muscle, this process seems likely to be related directly to force generation. In the GAP-ras system, measurement of phosphate release is allowing the mechanism of the GAP-p21ras interaction to be probed.

Plasmalemma localisation of inorganic phosphate in B cells pancreas

1978 ◽  
Vol 36 (2) ◽  
pp. 528-529
Author(s):  
F. B. P. Wooding ◽  
K. Pedley ◽  
N. Freinkel ◽  
R. M. C. Dawson
Keyword(s):  
Electron Microscope ◽  
B Cells ◽  
B Cell ◽  
Pancreatic Islets ◽  
High Glucose ◽  
Lead Acetate ◽  
Inorganic Phosphate ◽  
Slight Modification ◽  
Uranyl Acetate ◽  
Lead Phosphate

Freinkel et al (1974) demonstrated that isolated perifused rat pancreatic islets reproduceably release up to 50% of their total inorganic phosphate when the concentration of glucose in the perifusion medium is raised.Using a slight modification of the Libanati and Tandler (1969) method for localising inorganic phosphate by fixation-precipitation with glutaraldehyde-lead acetate we can demonstrate there is a significant deposition of lead phosphate (identified by energy dispersive electron microscope microanalysis) at or on the plasmalemma of the B cell of the islets (Fig 1, 3). Islets after incubation in high glucose show very little precipitate at this or any other site (Fig 2). At higher magnification the precipitate seems to be intracellular (Fig 4) but since any use of osmium or uranyl acetate to increase membrane contrast removes the precipitate of lead phosphate it has not been possible to verify this as yet.

Effects of pH on proton transport by vacuolar pumps from maize roots

1992 ◽  
Vol 86 (1) ◽  
pp. 63-70 ◽  
Author(s):  
David Brauer ◽  
DeNea Conner ◽  
Shu-I Tu
Keyword(s):  
Proton Transport ◽  
Maize Roots ◽  
Effects Of Ph

Differences in Subcellular Distribution of Catechol-O-Methyltransferase and Tyrosinase in Malignant Melanoma

1993 ◽  
Vol 100 ◽  
pp. 222S-225S ◽  
Author(s):  
Takakazu Shibata ◽  
Stan Pavel ◽  
Nico P M Smit ◽  
Yutaka Mishima
Keyword(s):  
Malignant Melanoma ◽  
Subcellular Distribution

Relation between intravascular electrolyte level and course of parturition in dairy cows

2013 ◽  
Vol 41 (05) ◽  
pp. 289-296 ◽  
Author(s):  
K. Seyrek-Intas ◽  
K. Failing ◽  
G. Yilmazbas Mecitoglu ◽  
H. Bostedt ◽  
D. Seyrek-Intas
Keyword(s):  
Dairy Cows ◽  
Inorganic Phosphate ◽  
Post Partum ◽  
Total Calcium ◽  
Normal Delivery ◽  
P Values ◽  
Normal Birth ◽  
Factors Influencing ◽  
Electrolyte Homeostasis ◽  
Convalescence Phase

Summary Objective: To determine the intravascular electrolyte status in dairy cows with respect to age and different courses of parturition to clarify etiological factors influencing peri- or intrapartal imbalances of electrolyte homeostasis. Material and methods: A total of 64 cows at birth were evaluated (primiparous n = 34, pluriparous n = 30). Thirty-three cows showed normal delivery, while 31 cows had a complicated birth. Blood samples were collected intra partum (i. p.) and 2, 4, 6, 8, 12, 16, 24 h post partum (p. p.) as well as [2, 3, 4, 5, 7, 10 days p. p. and levels of total calcium (Catotal), ionized calcium (Caion), inorganic phosphate (Pa), Mg, Na, K, Cl were determined. Results: The results revealed that electrolytes show great fluctuation during and immediately p. p. in relation to age. Already during parturition pluriparous cows had a lower Catotal and Pa concentration compared to primiparous animals. Cows with dystocia exhibited a more intensive and longer lasting decrease of Ca compared to cows with normal birth. In relation to age and severity of birth Pa concentration showed a differing but basically typical course for this electrolyte. Mg, Na, K and Cl concentrations were higher during and immediately after birth compared to p. p. values. Until day 10 p. p. these electrolyte concentrations declined more in older cows with dystocia compared to younger animals. However, the influence of dystocia on concentration of these electrolytes was milder in contrast to Ca and Pa. Conclusions: In summary, primarily older cows are predisposed to imbalances of electrolyte homeostasis intra partum and at the beginning of the lactation. These changes are potentiated in case of complications during parturition. Intravascular Catotal, Caion as well as Pa are most severely affected. Clinical relevance: These results may constitute the basis for a comprehensive metaphylaxis during the peripartal period, especially in cows after dystocia, to positively influence the early convalescence phase.

Biomimetic Extracellular Vesicles Embedded with Black Phosphorus for Molecular Recognition-Guided Biomineralization

2018 ◽  
Author(s):  
Yingqian Wang ◽  
Xiaoxia Hu ◽  
Lingling Zhang ◽  
Chunli Zhu ◽  
Jie Wang ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Extracellular Vesicles ◽  
Inorganic Phosphate ◽  
Physiological Activity ◽  
Medical Engineering ◽  
Matrix Vesicles ◽  
Black Phosphorus ◽  
Photothermal Effect ◽  
Biological Processes ◽  
Extracellular Environment

Extracellular vesicles (EVs) are involved in the regulation of cell physiological activity and the reconstruction of extracellular environment. Matrix vesicles (MVs) are a type of EVs, and they participate in the regulation of cell mineralization. Herein, bioinspired MVs embedded with black phosphorus are functionalized with cell-specific aptamer (denoted as Apt-bioinspired MVs) for stimulating biomineralization. The aptamer can direct bioinspired MVs to targeted cells, and the increasing concentration of inorganic phosphate originated from the black phosphorus can facilitate cell biomineralization. The photothermal effect of the Apt-bioinspired MVs also positively affects mineralization. In addition, the Apt-bioinspired MVs display outstanding bone regeneration performance. Considering the excellent behavior of the Apt-bioinspired MVs for promoting biomineralization, our strategy provides a way of designing bionic tools for studying the mechanisms of biological processes and advancing the development of medical engineering.<br>

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