The subcellular distribution and properties of Crithidia sp. hydrolases with particular reference to pyrophosphate and orthophosphate monoester phosphohydrolases

1976 ◽  
Vol 54 (4) ◽  
pp. 365-381 ◽  
Author(s):  
J. McLaughlin ◽  
H. S. Injeyan ◽  
E. Meerovitch
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Hydrolytic Enzymes ◽  
Hydrolytic Activity ◽  
Cell Fractionation ◽  
Acid Hydrolases ◽  
Mitochondrial Marker ◽  
Fractionation Scheme ◽  
A Cell

A cell fractionation scheme was developed for studying the distribution of certain hydrolases, especially phosphohydrolases, in a Crithidia sp. (Trypanosomatidae). Whilst between 26–56% of the total cellular hydrolase activities were soluble (probably of flagellar pocket origin), a certain percentage, 5–40%, was sedimentable. A particulate fraction obtained after isopycnic density gradient centrifugation (ρ = 1.187–1.241), designated fraction FA/FB, was enriched in various acid hydrolases (relative specific activities 1.33–6.24) and displayed latent phosphohydrolase activities. The density gradient distributions of these hydrolytic enzymes were compared with reference to one another and malate dehydrogenase (mitochondrial marker). From the results obtained it appears that the sedimentable acid hydrolases of Crithidia are associated with a heterogeneous population of subcellular particles. Cytochemical observations on the FA/FB fraction supported this finding and revealed the association of acid phosphatase reaction product with subcellular elements resembling multivesicular bodies.A detailed study of the hydrolytic activity toward both ortho- and pyrophosphate substrates by the soluble, as compared to the FA/FB fractions, revealed the existence of distinct phosphohydrolase activities. It is proposed that these differences in properties are due to the existence of phosphohydrolase isoenzymes and that they in turn relate to a differentiation in the cellular digestive functions of Crithidia.

scholarly journals The subcellular loclization and properties of the ferrochelatase of etiolated barley

1976 ◽  
Vol 156 (2) ◽  
pp. 309-314 ◽  
Author(s):  
H N Little ◽  
O T G Jones
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Mitochondrial Fraction ◽  
Marker Enzymes ◽  
Mitochondrial Marker

The etioplast fraction prepared from dark-grown barley contained the enzyme ferrochelatase. A mitochondrial fraction prepared from the same dark-grown tissue also contained ferrochelatase. After density-gradient centrifugation an etioplast band was collected that was free from detectable mitochondrial marker enzymes and yet retained ferrochelatase activity. A membrane band that was enriched in mitochondria also contained ferrochelatase. The ferrochelatase in these two bands had different pH optima, but appeared very similar in their porphyrin specificity and their inhibition by metalloporphyrins.

scholarly journals Isolation of bacteria from artificial bronchoalveolar lavage fluid using density gradient centrifugation and their accessibility by Raman spectroscopy

2021 ◽  
Author(s):  
Christina Wichmann ◽  
Petra Rösch ◽  
Jürgen Popp
Keyword(s):  
Raman Spectroscopy ◽  
Bronchoalveolar Lavage ◽  
Density Gradient ◽  
Bronchoalveolar Lavage Fluid ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Lavage Fluid ◽  
Biochemical Properties ◽  
Low Concentrations ◽  
A Cell

AbstractRaman spectroscopy is an analytical method to identify medical samples of bacteria. Because Raman spectroscopy detects the biochemical properties of a cell, there are many factors that can influence and modify the Raman spectra of bacteria. One possible influence is a proper method for isolation of the bacteria. Medical samples in particular never occur in purified form, so a Raman-compatible isolation method is needed which does not affect the bacteria and thus the resulting spectra. In this study, we present a Raman-compatible method for isolation of bacteria from bronchoalveolar lavage (BAL) fluid using density gradient centrifugation. In addition to measuring the bacteria from a patient sample, the yield and the spectral influence of the isolation on the bacteria were investigated. Bacteria isolated from BAL fluid show additional peaks in comparison to pure culture bacteria, which can be attributed to components in the BAL sample. The isolation gradient itself has no effect on the spectra, and with a yield of 63% and 78%, the method is suitable for isolation of low concentrations of bacteria from a complex matrix.

Uranyl Acetate and Rotary Shadowing to Increase the Contrast of Small Aggregated Virus Particles

1969 ◽  
Vol 27 ◽  
pp. 424-425
Author(s):  
Lee F. Ellis ◽  
Richard M. Van Frank ◽  
Walter J. Kleinschmidt
Keyword(s):  
Electron Microscopy ◽  
Tissue Culture ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Uranyl Acetate ◽  
Interferon Inducer ◽  
Virus Particles ◽  
Staining Methods ◽  
Rotary Shadowing

The extract from Penicillum stoliniferum, known as statolon, has been purified by density gradient centrifugation. These centrifuge fractions contained virus particles that are an interferon inducer in mice or in tissue culture. Highly purified preparations of these particles are difficult to enumerate by electron microscopy because of aggregation. Therefore a study of staining methods was undertaken.

The Combining Ability of Glycoproteins IIb, IIIa and Ca2+ in EDTA-Treated Nonaggregable Platelets

1983 ◽  
Vol 50 (04) ◽  
pp. 848-851 ◽  
Author(s):  
Marjorie B Zucker ◽  
David Varon ◽  
Nicholas C Masiello ◽  
Simon Karpatkin
Keyword(s):  
Density Gradient ◽  
Combining Ability ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Electrophoretic Pattern ◽  
Sucrose Density Gradient ◽  
Irreversible Loss ◽  
Sucrose Density Gradient Centrifugation ◽  
Crossed Immunoelectrophoresis ◽  
Triton X

SummaryPlatelets deprived of calcium and incubated at 37° C for 10 min lose their ability to bind fibrinogen or aggregate with ADP when adequate concentrations of calcium are restored. Since the calcium complex of glycoproteins (GP) IIb and IIIa is the presumed receptor for fibrinogen, it seemed appropriate to examine the behavior of these glycoproteins in incubated non-aggregable platelets. No differences were noted in the electrophoretic pattern of nonaggregable EDTA-treated and aggregable control CaEDTA-treated platelets when SDS gels of Triton X- 114 fractions were stained with silver. GP IIb and IIIa were extracted from either nonaggregable EDTA-treated platelets or aggregable control platelets with calcium-Tris-Triton buffer and subjected to sucrose density gradient centrifugation or crossed immunoelectrophoresis. With both types of platelets, these glycoproteins formed a complex in the presence of calcium. If the glycoproteins were extracted with EDTA-Tris-Triton buffer, or if Triton-solubilized platelet membranes were incubated with EGTA at 37° C for 30 min, GP IIb and IIIa were unable to form a complex in the presence of calcium. We conclude that inability of extracted GP IIb and IIIa to combine in the presence of calcium is not responsible for the irreversible loss of aggregability that occurs when whole platelets are incubated with EDTA at 37° C.

scholarly journals Sperm selection of cryopreserved milt of catfish (Rhamdia quelen) by density gradient centrifugation with AllGrad® 90%

MethodsX ◽  
2021 ◽  
pp. 101422
Author(s):  
Maritza Pérez Atehortúa ◽  
Andrea Galuppo ◽  
Rômulo Batista Rodrigues ◽  
Nathalia dos Santos Teixeira ◽  
Thaiza Rodrigues de Freitas ◽  
...  
Keyword(s):  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sperm Selection ◽  
Rhamdia Quelen ◽  
Selection Of
Sign in / Sign up

Export Citation Format

Share Document