Localization of 5?-nucleotidase in bovine brain myelin fraction and myelin subfractions

1988 ◽  
Vol 13 (4) ◽  
pp. 359-368 ◽  
Author(s):  
Vicent Casad� ◽  
Josefa Mallol ◽  
Jorge Bozal
Keyword(s):  
Bovine Brain ◽  
Myelin Subfractions ◽  
Myelin Fraction

scholarly journals UDP-galactose-ceramide galactosyltransferase in rat brain myelin subfractions during development

1980 ◽  
Vol 186 (3) ◽  
pp. 959-969 ◽  
Author(s):  
O Koul ◽  
K H Chou ◽  
F B Jungalwala
Keyword(s):  
Rat Brain ◽  
Membrane Fraction ◽  
Specific Activity ◽  
Gradient Centrifugation ◽  
Proteolipid Protein ◽  
Myelin Proteins ◽  
Sucrose Density Gradient Centrifugation ◽  
Microsomal Membranes ◽  
Myelin Subfractions ◽  
Myelin Fraction

The localization and activity of the enzyme UDP-galactose-hydroxy fatty acid-containing ceramide galactosyltransferase is described in rat brain myelin subfractions during development. Other lipid-synthesizing enzymes, such as cerebroside sulphotransferase, UDP-glucose-ceramide glucosyltransferase and CDP-choline-1,2-diacylglycerol cholinephosphotransferase, were also studied for comparison in myelin subfractions and microsomal membranes. The purified myelin was subfractionated by isopycnic sucrose-density-gradient centrifugation. Four myelin subfractions, three floating respectively on 0.55 M- (light-myelin fraction), 0.75 M- (heavy-myelin fraction) and 0.85 M-sucrose (membrane fraction), and a pellet, were isolated and purified. At all ages, 70-75% of the total myelin proteins was found in the heavy-myelin fraction, whereas 2-5% of the protein was recovered in the light-myelin fraction, and about 7-12% in the membrane fraction. Most of the galactosyltransferase was associated with the heavy-myelin and membrane fractions. Other lipid-synthesizing enzymes studied appeared not to associate with purified myelin or myelin subfractions, but were enriched in the microsomal-membrane fraction. During development, the specific activity of the microsomal galactosyltransferase reached a maximum when the animals were about 20 days old and then declined. By contrast the specific activity of the galactosyltransferase in the heavy-myelin and membrane fractions was 3-4 times higher than that of the microsomal membranes in 16-day-old animals. The specific activity of the enzyme in the heavy-myelin fraction sharply declined with age. Chemical and enzymic analyses of the heavy-myelin and membrane myelin subfractions at various ages showed that the membrane fraction contained more proteins in relation to lipids than the heavy-myelin fraction. The membrane fraction was also enriched in phospholipids compared with cholesterol and contrined equivalent amounts of 2':3'-cyclic nucleotide 3'-phosphohydrolase compared with heavy- and light-myelin fractions. The membrane fraction was deficient in myelin basic protein and proteolipid protein and enriched in high-molecular-weight proteins. The specific localization of galactosyltransferase in heavy-myelin and membrane fractions at an early age when myelination is just beginning suggests that it may have some role in the myelination process.

scholarly journals Enzymic methylation of myelin basic protein in myelin

1991 ◽  
Vol 275 (2) ◽  
pp. 381-387 ◽  
Author(s):  
S K Ghosh ◽  
N Rawal ◽  
S K Syed ◽  
W K Paik ◽  
S D Kim
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Arginine Methylation ◽  
Specific Protein ◽  
Bovine Brain ◽  
Exchange Chromatography ◽  
Myelin Proteins ◽  
Associated Proteins ◽  
Myelin Fraction ◽  
A Charge

Myelin fractions with different degrees of compaction were isolated from bovine brain, and post-translational methylation of membrane-associated proteins was studied. When the purified myelin-basic-protein-specific protein methylase I and S-adenosyl-L-[methyl-14C]methionine were added exogenously, the most compact myelin fraction exhibited higher methyl-accepting activity than the less compact dense fractions. The methylated protein was identified as myelin basic protein (18.4 kDa) exclusively among the several myelin proteins from all membrane fractions, by SDS/PAGE/radioautography of methyl-14C-labelled membrane proteins. The methyl-14C-labelled amino acid residue in the basic protein was identified by h.p.l.c. as NG-methylarginine, indicating the high degree of specificity for the arginine residue as well as the myelin basic protein in the intact myelin membranes. The possibility of a charge alteration of myelin basic protein resulting from its arginine methylation was investigated by using the purified component 1 of myelin basic protein. The methylated component was shown to be less cationic than the unmethylated component by Bio-Rex 70 cation-exchange chromatography, since the former preceded the latter. However, in the presence of the denaturant (guanidinium chloride), the two species were co-eluted, indicating that the charge difference between methylated and unmethylated myelin basic protein can only be shown under the renatured condition.

The Strong Positive Correlation between Factor VII Clotting Activity Using Bovine Thromboplastin and the Activated Factor VII Level

1995 ◽  
Vol 73 (03) ◽  
pp. 429-434 ◽  
Author(s):  
Kazuomi Kario ◽  
Takefumi Matsuo ◽  
Reiko Asada ◽  
Toshiyuki Sakata ◽  
Hisao Kato ◽  
...  
Keyword(s):  
Risk Factor ◽  
Bovine Brain ◽  
Factor Vii ◽  
Rabbit Brain ◽  
Strong Positive Correlation ◽  
Chromogenic Substrate ◽  
Moderate Correlation ◽  
Positive Correlation ◽  
Activated Factor Vii

SummaryWe compared factor VII clotting activity (FVIIc) assays using different thromboplastins to determine which is the most sensitive for activated FVII (FVIIa) or for FVII antigen (FVIIag). FVIIc levels were measured using thromboplastins derived from bovine brain (FVIIc Bov), human placenta (FVIIc Hum), and rabbit brain (FVIIc Rab). FVIIa levels were measured by fluorogenic assays using human soluble tissue factor (rsTF) or bovine rsTF. We also measured FVII activity by an amidolytic assay (FVIIc:am Hum) using human thromboplastin and a chromogenic substrate for thrombin. FVIIag levels were determined by ELISA. In the FVIIa assay, the reaction time obtained from using bovine rsTF was shorter than that with human rsTF, suggesting that the interaction of plasma FVIIa with bovine rsTF was stronger than with human rsTF. The plasma FVIIa levels measured using human rsTF and bovine rsTF were almost the same (r=0.947, p<0.0001). Among the three FVIIc assays, FVIIc Bov had the strongest positive correlation with the plasma FVIIa level (r=0.886, p<0.000l), but had no correlation with FVIIag. An increase of 1 ng/ml in the plasma FVIIa level yielded a 27.9% increase of FVIIc Bov. Plasma FVIIc Hum and FVIIc:am Hum showed moderate correlations with both FVIIa (r=0.520, p<0.02 and r=0.569, p<0.01, respectively) and FVIIag (r=0.438, p<0.05 and r=0.468, p<0.05, respectively). FVIIc Rab had the lowest correlation with FVIIa (r=0.367, p<0.1), but had a moderate correlation with FVIIag (r=0.436, p<0.05). After in vitro cold activation, FVIIc Bov levels increased the most and FVIIc:am levels showed the least change. These findings indicate that consideration of the thromboplastin used for assay is necessary when assessing the clinical significance of FVII activity as a cardiovascular risk factor.

THE LESS-POLAR METABOLITES PRODUCED BY INCUBATION OF TESTOSTERONE-4-14C WITH RAT AND BOVINE BRAIN

1969 ◽  
Vol 61 (4) ◽  
pp. 641-648 ◽  
Author(s):  
Leon J. Sholiton ◽  
Emile E. Werk
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Paper Chromatography ◽  
Specific Activity ◽  
Bovine Brain ◽  
Polar Fraction ◽  
End Products ◽  
Polar Metabolites ◽  
Layer Chromatography ◽  
Constant Specific Activity

ABSTRACT Rat and bovine brain have been incubated with testosterone-4-14C under standard conditions. With use of paper chromatography, the extracted metabolites were noted to fall into less-polar, iso-polar, and more polar fractions. The components of the less-polar fraction were separated by acetylation and thin-layer chromatography and the major end-products identified by recrystallization to constant specific activity or constant 3H/14C ratios. Androst-4-enedione and 5α-dihydrotestosterone were formed consistently under the conditions utilized. Trace amounts of other less-polar metabolites were noted occasionally.

Identification of a Coronavirus Hemagglutinin-Esterase with a Substrate Specificity Different from Those of Influenza C Virus and Bovine Coronavirus

1999 ◽  
Vol 73 (5) ◽  
pp. 3737-3743 ◽  
Author(s):  
Alfred Klausegger ◽  
Birgit Strobl ◽  
Gerhard Regl ◽  
Alexandra Kaser ◽  
Willem Luytjes ◽  
...  
Keyword(s):  
Substrate Specificity ◽  
Solid Phase ◽  
Hepatitis Virus ◽  
Bovine Brain ◽  
Brain Extract ◽  
Binding Assays ◽  
Bovine Coronavirus ◽  
Close Relationship ◽  
Influenza C Virus ◽  
Cloned Gene

ABSTRACT We have characterized the hemagglutinin-esterase (HE) of puffinosis virus (PV), a coronavirus closely related to mouse hepatitis virus (MHV). Analysis of the cloned gene revealed approximately 85% sequence identity to HE proteins of MHV and approximately 60% identity to the corresponding esterase of bovine coronavirus. The HE protein exhibited acetylesterase activity with synthetic substratesp-nitrophenyl acetate, α-naphthyl acetate, and 4-methylumbelliferyl acetate. In contrast to other viral esterases, no activity was detectable with natural substrates containing 9-O-acetylated sialic acids. Furthermore, PV esterase was unable to remove influenza C virus receptors from human erythrocytes, indicating a substrate specificity different from HEs of influenza C virus and bovine coronavirus. Solid-phase binding assays revealed that purified PV was unable to bind to sialic acid-containing glycoconjugates like bovine submaxillary mucin, mouse α1macroglobulin or bovine brain extract. Because of the close relationship to MHV, possible implications on the substrate specificity of MHV esterases are suggested.

scholarly journals Purification of the neurotensin receptor from bovine brain.

1988 ◽  
Vol 263 (1) ◽  
pp. 13-16
Author(s):  
A Mills ◽  
C D Demoliou-Mason ◽  
E A Barnard
Keyword(s):  
Bovine Brain ◽  
Neurotensin Receptor
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