Distribution of selected phospholipid modifying enzymes in rat brain microsomal subfractions prepared by density gradient zonal rotor centrifugation

1985 ◽  
Vol 10 (4) ◽  
pp. 439-451 ◽  
Author(s):  
Vinay S. Bansal ◽  
Hiroshi Hattori ◽  
Danka Orihel ◽  
Julian N. Kanfer
1967 ◽  
Vol 45 (5) ◽  
pp. 671-688 ◽  
Author(s):  
M. W. Spence ◽  
L. S. Wolfe

Neurones in the central nervous system of vertebrates contain considerable amounts of a complex group of acidic glycosphingolipids, the gangliosides. Determination of gangliosides, cholesterol, phospholipid phosphorus, neutral glycolipid hexose, and protein in developing rat brain showed that the deposition of gangliosides is predominantly a premyelin event. A light membrane fraction enriched in gangliosides relative to protein was obtained from neonatal rat-brain crude mitochondrial fractions by sucrose density-gradient centrifugations. Adult rat-brain fractions of similar density were not enriched in gangliosides because of the presence of myelin. If the initial homogenization and the separation of the crude mitochondrial fraction were carried out in 0.32 M sucrose at pH 9.2, the ganglioside enrichment of the light membrane fraction from both adult and neonatal rat brain was doubled. By further separation of the light membrane fraction on a second density gradient, particulate material was obtained from neonatal rat brain which consisted almost entirely of vesicular membrane elements. Based on dry weight, it contained gangliosides 7–9%, phospholipids 36–40%, cholesterol 5–7%, neutral glycolipids 1–3%, protein 28–29%, and cations (Na+, K+, Ca2+, Mg2+) 8%. This membrane fraction is likely derived from the neuronal plasma membrane or the endoplasmic reticulum.


1983 ◽  
Vol 37 (5) ◽  
pp. 354-360 ◽  
Author(s):  
Hector Coirini ◽  
Elisa T. Marusic ◽  
Alejandro F. De Nicola ◽  
Thomas C. Rainbow ◽  
Bruce S. McEwen

1966 ◽  
Vol 30 (2) ◽  
pp. 405-415 ◽  
Author(s):  
H. Løvtrup-Rein ◽  
B. S. McEwen

A method for isolating pure and unaltered nuclei from rat brain by means of differential centrifugation is described. The isolated nuclei are further separated into discrete fractions of neuronal, astrocytic, and glial nuclei, with a yield amounting to 20 to 25% of the DNA of the original homogenate. Both the morphology and size of the nuclei remained unchanged. Problems concerning the composition of the isolation media, the use of detergents, as well as those raised by density gradient centrifugation in sucrose, Ficoll, and Dextran are discussed. Some values for the density of each type of brain nuclei are suggested.


1976 ◽  
Vol 68 (1) ◽  
pp. 5-12 ◽  
Author(s):  
C. N. A. TROTMAN ◽  
I. J. S. FIDDES ◽  
E. R. GRUND ◽  
S. McHANWELL ◽  
D. J. SANDERS ◽  
...  

SUMMARY Immunoreactive gastrin was measured in subcellular fractions of rat gastric mucosa. The sedimentational properties of subcellular gastrin-containing structures were distinct from those of mitochondria. After centrifugation in sucrose density gradients using a zonal rotor, the peak of immunoreactive gastrin was found in 1·17–1·18 g cm−3 density sucrose (1·35 m; 39·5%, w/w). A thermolabile component with 125I-labelled gastrin-binding activity present in gastric mucosal homogenates and fractions was not associated with the gastrin storage vesicles sedimenting in density gradients.


1975 ◽  
Vol 152 (3) ◽  
pp. 601-607 ◽  
Author(s):  
H J Hilderson ◽  
M J De Wolf ◽  
A R Lagrou ◽  
W S Dierick

A combined mitochondrial and light mitochondrial fraction and a microsomal fraction were isolated from bovine thyroid gland and fractionated further in a B-XIV zonal rotor. A density gradient ranging from 20 to 50% (w/w) sucrose was used. The rotor was operated for 3 h at 45 000 rev./min. All manipulations were performed at 4 degrees C and at pH 7.4. 2. Membranous material was recovered in two zones: zone I, containing microsomal material derived from both smooth endoplasmic reticulum and plasma membranes and probably also from other smooth membranes; zone II, containing material from rough endoplasmic reticulum. 3. Increasing the pH of the medium up to 8.6, or the addition of Mg2+ to the medium resulted in the formation of a single zone at intermediate densities (aggregation of membranes?). An analogous effect was obtained after treatment with Pb (NO3) 2. 4. In the presence of heparin (50 i.u./ml) the bulk of the membranes was found in zone I. This was due to the release of ribosomes from the rough endoplasmic reticulum.


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