scholarly journals A rapid procedure for selectively isolating the major glycoprotein from purified rat brain myelin

1977 ◽  
Vol 163 (3) ◽  
pp. 635-637 ◽  
Author(s):  
R H Quarles ◽  
C F Pasnak
Keyword(s):  
Rat Brain ◽  
Aqueous Phase ◽  
The Other ◽  
Insoluble Residue ◽  
Rapid Procedure ◽  
Myelin Associated Glycoprotein ◽  
Chloroform Methanol

Treatment of the chloroform/methanol-insoluble residue of rat brain myelin with lithium 3,5-di-iodosalicylate solubilized the major myelin-associated glycoprotein along with most other proteins and glycoproteins. Equilibration of the extract with phenol resulted in the selective partitioning of the major glycoprotein into the aqueous phase, whereas nearly all of the other proteins and glycoproteins went into the phenol phase.

scholarly journals Lectin-binding proteins in central-nervous-system myelin. Binding of glycoproteins in purified myelin to immobilized lectins

1979 ◽  
Vol 183 (2) ◽  
pp. 213-221 ◽  
Author(s):  
Richard H. Quarles ◽  
Laurence J. McIntyre ◽  
Carol F. Pasnak
Keyword(s):  
Rat Brain ◽  
Concanavalin A ◽  
Sodium Dodecyl Sulphate ◽  
Lectin Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Preceding Paper ◽  
The Other ◽  
Double Labelling ◽  
Myelin Associated Glycoprotein

The capacities of immature and mature rat brain myelin, bovine myelin and human myelin to be agglutinated by soya-bean agglutinin, Ricinus communis agglutinin, wheatgerm agglutinin, and Lotus tetragonolobus agglutinin were examined. The first two lectins, which are specific for galactose and N-acetylgalactosamine, strongly agglutinated immature and mature rat myelin, weakly agglutinated bovine myelin, but did not affect human myelin. The other myelin and lectin combinations resulted in very weak or no agglutination. [3H]Fucose-labelled glycoproteins of purified adult rat brain myelin were solubilized with sodium dodecyl sulphate and allowed to bind to concanavalin A–Sepharose and each of the other lectins mentioned above, which had been immobilized on agarose. About 60% of the radioactive fucose was in glycoproteins that bound to concanavalin A–Sepharose and these glycoproteins could be eluted with solutions containing methyl α-d-mannoside and sodium dodecyl sulphate. Periodate/Schiff staining or radioactive counting of analytical gels showed that most of the major myelin-associated glycoprotein (apparent mol.wt. approx. 100000) bound to the concanavalin A, whereas the glycoproteins that did not bind were mostly of lower molecular weight. Preparative polyacrylamide-gel electrophoresis of the glycoprotein fraction that was eluted with methyl α-d-mannoside yielded a relatively pure preparation of the myelin-associated glycoprotein. Similar results were obtained with each of the other lectins, i.e. the myelin-associated glycoprotein was in the fraction that bound to the immobilized lectin. Double-labelling experiments utilizing [3H]fucose-labelled glycoproteins from adult myelin and [14C]fucose-labelled glycoproteins from 14-day-old rat brain myelin did not reveal any difference in the binding of the mature and immature glycoproteins to any of the immobilized lectins. The results in this and the preceding paper [McIntyre, Quarles & Brady (1979) Biochem. J.183, 205–212] suggest that the myelin-associated glycoprotein is one of the principal receptors for concanavalin A and other lectins in myelin, and that this property can be utilized for the purification of this glycoprotein.

METABOLISM OF AROMATIC COMPOUNDS IN HEALTHY AND RUST-INFECTED PRIMARY LEAVES OF WHEAT: II. STUDIES WITH L-PHENYLALANINE-U-14C, L-TYROSINE-U-14C, AND FERULATE-U-14C

1967 ◽  
Vol 45 (11) ◽  
pp. 2137-2153 ◽  
Author(s):  
A. Fuchs ◽  
R. Rohringer ◽  
D. J. Samborski
Keyword(s):  
Amino Acids ◽  
Stem Rust ◽  
Aromatic Compounds ◽  
The Other ◽  
Major Portion ◽  
Insoluble Residue ◽  
Resistant Reaction ◽  
Wheat Leaves

Wheat leaves infected with stem rust, especially those of susceptible plants, contained more phenylalanine and tyrosine than healthy leaves. The utilization of phenylalanine was increased in both the susceptible and resistant reaction, but the utilization of tyrosine was increased only in the susceptible reaction. No evidence of interconversion of these amino acids was obtained.In n-butanol extracts, which contained glycosides, many constituents were labelled after feeding of L-phenylalanine-U-14C. Most of the n-butanol extractives from resistant-reacting leaves contained more label than those from susceptible-reacting leaves or from healthy leaves. However, one of the n-butanol extractives from susceptible-reacting leaves was 5–10 times as active as that isolated from the other tissues.With L-phenylalanine-U-14C and ferulate-U-14C as precursors, more activity was recovered in insoluble than in soluble esters (of ferulate and p-coumarate). With L-tyrosine-U-14C as precursor, the reverse was observed. After infection, the proportion of label in insoluble esters increased more in resistant leaves than it did in susceptible leaves, regardless of the precursor used.A major portion of the activity from these precursors was recovered in the insoluble residue that contained protein and other polymers. In the experiment with L-phenylalanine-U-14C, this residue was fractionated into protein and non-hydrolyzable material. Susceptible-reacting leaves contained equal amounts of activity in these fractions, while resistant-reacting leaves incorporated 2.5 times as much activity into the non-hydrolyzable material as into protein.

FURTHER STUDIES ON THE BINDING OF γ-AMINOBUTYRIC ACID BY BRAIN

1967 ◽  
Vol 45 (12) ◽  
pp. 1795-1807 ◽  
Author(s):  
Paula Strasberg ◽  
K. A. C. Elliott
Keyword(s):  
Rat Brain ◽  
Mitochondrial Fraction ◽  
Sodium Ion ◽  
The Other ◽  
Aminobutyric Acid ◽  
Sodium Ions ◽  
Ninhydrin Reaction ◽  
Gaba Content

Factors which can interfere with the paper chromatographic – ninhydrin method for determining γ-aminobutyric acid (GABA) are described. The GABA–ninhydrin reaction does not involve loss of CO2. GABA that is occluded in subcellular particles in plain sucrose homogenates of rat brain does not readily exchange with radioactive GABA in solution. The relevant particles are found mostly in the "mitochondrial fraction". These particles deteriorate with time and manipulations, and tend to lose much of their GABA content. The presence of sodium (but not of potassium, calcium, or magnesium) in the suspending medium allows considerably more GABA to be bound. The extra bound GABA is exchangeable with free labelled GABA. Sodium also promotes some exchange between free and occluded GABA. It is concluded from the present and previous results that in brain in vivo very little GABA exists in a freely diffusing situation. There are two forms of bound GABA. One of these is an occluded or storage form which does not readily exchange with free GABA though exchange is to some extent promoted by sodium ions. The other is a form which occurs only in the presence of sodium ion and is freely exchangeable with GABA in solution.

The Chromatography of Rubber Solutions

1939 ◽  
Vol 12 (4) ◽  
pp. 762-773 ◽  
Author(s):  
Giampietro Cajelli
Keyword(s):  
Elastic Properties ◽  
Potassium Hydroxide ◽  
The Other ◽  
Precipitation Method ◽  
Insoluble Residue ◽  
Fractional Precipitation ◽  
Micellar Structure ◽  
X Ray ◽  
Colored Product ◽  
Considerable Doubt

Abstract In the opinion of Pummerer, there is considerable doubt about the homogeneity of the fractions obtained by fractional precipitation of rubber from dilute benzene solutions, both with respect to the size of the molecules and to the state of aggregation. Based on the results of x-ray measurements of fibrous substances, to which type stretched rubber belongs, Meyer and Mark have advanced the hypothesis of the existence of chains of primary valences and of a micellar structure. PURIFICATION OF RUBBER There are four important and at the same time essentially different ways of carrying out the difficult process of purifying rubber. According to Harries, acetone extraction gives a colored product and leads to profound changes in the elastic properties. Staudinger adopted the method described by Wildmann in 1911, which involves the use of a mixture of acetone and chloroform. On the other hand, Pummerer and Koch used the method of fractional precipitation; the rubber after severe mastication was extracted with acetone, was dissolved in benzene, the liquid was allowed to stand for several weeks, the solution was decanted from the insoluble residue and was fractionally precipitated by alcohol and acetone. More recently this same method has been perfected by Pummerer and Meidel, and by this means a fraction of crystallized rubber was isolated from the mother liquors of the fractional precipitation. Finally Pummerer and Koch have purified rubber by treatment with an alkali, combining the precipitation method with the use of a solution of potassium hydroxide in methanol. Later this method was modified by Pummerer and Pahl. The use of latex in place of crude rubber is the most important development in obtaining a satisfactory product. De Vries and Beumée-Nieuwland have described in detail some results obtained with fresh latex. The total-rubber obtained by the methods just described contains, according to the quality and the age of the sample of latex, from 0.1 to 0.4 per cent of nitrogen which cannot be removed by washing, even when this is exhaustive.

FREEZING DAMAGE TO BOVINE CREAM INDICATED BY RELEASE OF ENZYMES

1959 ◽  
Vol 37 (7) ◽  
pp. 821-827 ◽  
Author(s):  
L. J. N. Cole ◽  
D. Kluepfel ◽  
C. V. Lusena
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Xanthine Oxidase ◽  
Aqueous Phase ◽  
The Other ◽  
Rapid Freezing ◽  
Freezing Damage ◽  
Membrane Material ◽  
Fat Globules ◽  
Main Effect

When washed cream was frozen slowly and thawed, some breaking of the emulsion occurred and on centrifugation a pellet, mostly membrane material, was obtained. Xanthine oxidase and alkaline phosphatase were present in this pellet, but little enzyme activity was found in the aqueous phase. The main effect of slow freezing was to force the fat globules together so that alteration and redistribution of the membranes could occur, and, on thawing, fat could coalesce. Rapid freezing on the other hand distributed fat globules more evenly so that less coalescence could occur on thawing.

THE FORMATION OF GLYCEROPHOSPHATIDES FROM C14-LABELLED PRECURSORS IN RAT BRAIN SLICES

1958 ◽  
Vol 36 (11) ◽  
pp. 1211-1220 ◽  
Author(s):  
E. T. Pritchard
Keyword(s):  
Fatty Acid ◽  
Rat Brain ◽  
Carbohydrate Metabolism ◽  
Liver Tissue ◽  
Brain Slices ◽  
The Other ◽  
Aerobic Conditions ◽  
Liver Slices ◽  
Rat Brain And Liver ◽  
The Individual

The relative incorporation of a number of C14-labelled precursors into the phosphatides of surviving rat brain and liver slices was examined. In addition, the distribution of radioactivity within the individual phosphoglycerides was determined for each precursor. Acetate was the only precursor that contributed considerable radioactivity to the fatty acid portion of the phosphatide molecule. The other precursors donated their radioactivity to the non-fatty acid portion of the glycerophosphatide molecule, both in brain and liver tissue. In brain it was found that ethanolamine was the most effective precursor, followed by serine, choline, glycerol, acetate, and glycine. In liver the order was acetate, glycerol, serine, choline, and glycine. Aerobic conditions and an adequate carbohydrate metabolism were essential for optimum incorporation of the precursors into the phosphatides of brain slices.

THE FORMATION OF GLYCEROPHOSPHATIDES FROM C14-LABELLED PRECURSORS IN RAT BRAIN SLICES

1958 ◽  
Vol 36 (1) ◽  
pp. 1211-1220 ◽  
Author(s):  
E. T. Pritchard
Keyword(s):  
Fatty Acid ◽  
Rat Brain ◽  
Carbohydrate Metabolism ◽  
Liver Tissue ◽  
Brain Slices ◽  
The Other ◽  
Aerobic Conditions ◽  
Liver Slices ◽  
Rat Brain And Liver ◽  
The Individual

The relative incorporation of a number of C14-labelled precursors into the phosphatides of surviving rat brain and liver slices was examined. In addition, the distribution of radioactivity within the individual phosphoglycerides was determined for each precursor. Acetate was the only precursor that contributed considerable radioactivity to the fatty acid portion of the phosphatide molecule. The other precursors donated their radioactivity to the non-fatty acid portion of the glycerophosphatide molecule, both in brain and liver tissue. In brain it was found that ethanolamine was the most effective precursor, followed by serine, choline, glycerol, acetate, and glycine. In liver the order was acetate, glycerol, serine, choline, and glycine. Aerobic conditions and an adequate carbohydrate metabolism were essential for optimum incorporation of the precursors into the phosphatides of brain slices.

scholarly journals Assessment of Nuclear and Mitochondrial DNA, Expression of Mitochondria-Related Genes in Different Brain Regions in Rats after Whole-Body X-ray Irradiation

2020 ◽  
Vol 21 (4) ◽  
pp. 1196 ◽  
Author(s):  
Serazhutdin Abdullaev ◽  
Nina Gubina ◽  
Tatiana Bulanova ◽  
Azhub Gaziev
Keyword(s):  
Mitochondrial Dna ◽  
Rat Brain ◽  
Mitochondrial Biogenesis ◽  
Copy Number ◽  
Brain Regions ◽  
The Other ◽  
Whole Body ◽  
X Ray ◽  
Expression Of Genes ◽  
Time Point

Studies of molecular changes occurred in various brain regions after whole-body irradiation showed a significant increase in terms of the importance in gaining insight into how to slow down or prevent the development of long-term side effects such as carcinogenesis, cognitive impairment and other pathologies. We have analyzed nDNA damage and repair, changes in mitochondrial DNA (mtDNA) copy number and in the level of mtDNA heteroplasmy, and also examined changes in the expression of genes involved in the regulation of mitochondrial biogenesis and dynamics in three areas of the rat brain (hippocampus, cortex and cerebellum) after whole-body X-ray irradiation. Long amplicon quantitative polymerase chain reaction (LA-QPCR) was used to detect nDNA and mtDNA damage. The level of mtDNA heteroplasmy was estimated using Surveyor nuclease technology. The mtDNA copy numbers and expression levels of a number of genes were determined by real-time PCR. The results showed that the repair of nDNA damage in the rat brain regions occurs slowly within 24 h; in the hippocampus, this process runs much slower. The number of mtDNA copies in three regions of the rat brain increases with a simultaneous increase in mtDNA heteroplasmy. However, in the hippocampus, the copy number of mutant mtDNAs increases significantly by the time point of 24 h after radiation exposure. Our analysis shows that in the brain regions of irradiated rats, there is a decrease in the expression of genes (ND2, CytB, ATP5O) involved in ATP synthesis, although by the same time point after irradiation, an increase in transcripts of genes regulating mitochondrial biogenesis is observed. On the other hand, analysis of genes that control the dynamics of mitochondria (Mfn1, Fis1) revealed that sharp decrease in gene expression level occurred, only in the hippocampus. Consequently, the structural and functional characteristics of the hippocampus of rats exposed to whole-body radiation can be different, most significantly from those of the other brain regions.

Metabolism of a myelin-associated glycoprotein in developing rat brain

1974 ◽  
Vol 76 (3) ◽  
pp. 423-434 ◽  
Author(s):  
Mary J. Druse ◽  
Roscoe O. Brady ◽  
Richard H. Quarles
Keyword(s):  
Rat Brain ◽  
Myelin Associated Glycoprotein ◽  
Developing Rat

FREEZING DAMAGE TO BOVINE CREAM INDICATED BY RELEASE OF ENZYMES

1959 ◽  
Vol 37 (1) ◽  
pp. 821-827 ◽  
Author(s):  
L. J. N. Cole ◽  
D. Kluepfel ◽  
C. V. Lusena
Keyword(s):  
Alkaline Phosphatase ◽  
Enzyme Activity ◽  
Xanthine Oxidase ◽  
Aqueous Phase ◽  
The Other ◽  
Rapid Freezing ◽  
Freezing Damage ◽  
Membrane Material ◽  
Fat Globules ◽  
Main Effect

When washed cream was frozen slowly and thawed, some breaking of the emulsion occurred and on centrifugation a pellet, mostly membrane material, was obtained. Xanthine oxidase and alkaline phosphatase were present in this pellet, but little enzyme activity was found in the aqueous phase. The main effect of slow freezing was to force the fat globules together so that alteration and redistribution of the membranes could occur, and, on thawing, fat could coalesce. Rapid freezing on the other hand distributed fat globules more evenly so that less coalescence could occur on thawing.

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