The subcellular localization of transglutaminase in normal liver and in glucagon-treated and partial hepatectomized rats

1983 ◽  
Vol 3 (12) ◽  
pp. 1085-1090 ◽  
Author(s):  
Sally E. Bruce ◽  
Timothy J. Peters
Keyword(s):  
Plasma Membrane ◽  
Subcellular Distribution ◽  
Specific Activity ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Normal Liver ◽  
Sucrose Density Gradient ◽  
Subcellular Fractionation ◽  
Sucrose Density Gradient Centrifugation ◽  
Significant Difference

Rat liver was homogenized in isotonic sucrose and subjected to analytical subcellular fractionation by sucrose density-gradient centrifugation. Transglutaminase, when assayed with putrescine and dimethylcasein as substrates, showed three distinct localizations, cytosol (73%), plasma membrane (20%), and nuclei (7%). The distribution was unaffected by homogenization in the presence of potassium chloride, indicating that the particulate activity was not due to adsorbed cytosolic enzyme. The specific activity and subcellular distribution of transglutaminase in rats which had received intra-peritoneal glucagon, stimulating endocytosis; or which had been subjected to sub-total hepatectomy 2, 16, or 32 h previously, showed no significant difference from control animals.

scholarly journals Long-chain acyl-coenzyme A synthetase activity of spinach chloroplasts is concentrated in the envelope

1977 ◽  
Vol 162 (2) ◽  
pp. 457-459 ◽  
Author(s):  
P G Roughan ◽  
C R Slack
Keyword(s):  
Phospholipase D ◽  
Specific Activity ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Synthetase Activity ◽  
Sucrose Density Gradient Centrifugation ◽  
Chain Acyl ◽  
Acyl Coenzyme A ◽  
Long Chain

Purified chloroplasts were disrupted and then fractionated by discontinuous sucrose-density-gradient centrifugation. Envelopes contained long-chain acyl-CoA synthetase at a specific activity 80 times the activity in the lamellae or the stroma. Acetyl-CoA synthetase was concentrated in the stroma, and chlorophyll was confined to the lamellae membranes. Phospholipase D was not detected in any fraction.

The Organelle Pathology and Demonstration of Mitochondrial Superoxide Dismutase Deficiency in Two Patients with Dubin–Johnson–Sprinz Syndrome

1978 ◽  
Vol 54 (5) ◽  
pp. 549-553
Author(s):  
T. J. Peters ◽  
Carol A. Seymour
Keyword(s):  
Superoxide Dismutase ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Subcellular Fractionation ◽  
Sucrose Density Gradient Centrifugation ◽  
Mitochondrial Superoxide ◽  
Liver Biopsies ◽  
Mitochondrial Superoxide Dismutase

1. Liver biopsies from two patients with the Dubin—Johnson—Sprinz syndrome were subjected to analytical subcellular fractionation by sucrose-density-gradient centrifugation and enzymic micro-assays. 2. A selective deficiency of mitochondrial superoxide dismutase has been demonstrated in these patients. 3. The significance of this enzyme deficiency is discussed in relation to the organelle pathology of the syndrome.

scholarly journals Solubilization of pig lymphocyte plasma membrane and fractionation of some of the components

1971 ◽  
Vol 123 (5) ◽  
pp. 967-975 ◽  
Author(s):  
D. Allan ◽  
M. J. Crumpton
Keyword(s):  
Plasma Membrane ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Biological Activities ◽  
Gradient Centrifugation ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Sucrose Density Gradient ◽  
Similar Distribution ◽  
Sucrose Density Gradient Centrifugation

The degree of solubilization of pig lymphocyte plasma membrane by sodium deoxycholate was determined at a variety of temperatures and detergent concentrations. Approx. 95% of the membrane protein was soluble in 2% deoxycholate at 23°C. Some of the biological activities of the membrane survived this treatment. The leucine β-naphthylamidase activity was more readily soluble than the 5′-nucleotidase and these enzymes could be separated by extraction with 0.5% deoxycholate at 0°C. Membrane solubilized in 2% deoxycholate at 23°C was fractionated by sucrose-density-gradient centrifugation in 1% deoxycholate. The phospholipid was separated from the protein, which formed a fairly symmetrical peak that sedimented slightly slower than ovalbumin; the leucine naphthylamidase and 5′-nucleotidase activities were resolved from each other and from the main protein peak. Similar separations were achieved by elution from Sephadex G-200 and Sepharose 6B in 1% deoxycholate. The main proteins, however, appeared to possess much higher molecular weights than those indicated by sucrose-density-gradient centrifugation. This disparity suggests that many of the membrane proteins have a rod-like shape, especially since the results of experiments with [14C]deoxycholate revealed that the proteins did not bind significant amounts of deoxycholate. In contrast, 5′-nucleotidase and leucine naphthylamidase appeared to be globular. Polyacrylamide-gel electrophoresis of membrane solubilized in sodium dodecyl sulphate gave a similar distribution of protein to that achieved by sucrose-density-gradient centrifugation. Trace amounts only of polypeptides of molecular weight less than 10000 were detected.

Galactosyltransferase activity is not localized to the brush border membrane of human small intestine

1986 ◽  
Vol 6 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Frances Boyle ◽  
Susan Snape ◽  
Paul Duane ◽  
Neil Cook ◽  
Timothy Peters
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Subcellular Fractionation ◽  
Equilibrium Density ◽  
Sucrose Density Gradient Centrifugation ◽  
Human Small Intestine ◽  
Immunocytochemical Techniques

A recent report [Roth et al. (1985) J. Cell Biol.100: 118–125], using immunocytochemical techniques, calimed that human duodenal galactosyltransferase is located predominantly on the external aspect of enterocyte brush border membranes. Analytical subcellular fractionation by sucrose density gradient centrifugation of human jejunum biopsy homogenates demonstrated that galactosyltransferase activity is localized to the Golgi fraction (equilibrium density of 1.14 g cm−3) and is not found in significant amounts in the brush border membrane (equilibrium density of 1.22 g cm−3).

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