scholarly journals Partial characterization of the phosphotransferase system of human central-nervous-system myelin

1983 ◽  
Vol 209 (3) ◽  
pp. 789-795 ◽  
Author(s):  
N C Wu ◽  
J E Yourist ◽  
W D Rector ◽  
F Ahmad
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cyclic Nucleotide ◽  
Basic Protein ◽  
Phosphotransferase System ◽  
Human Central Nervous System ◽  
Bivalent Cation ◽  
Triton X ◽  
Modest Activity

The phosphotransferase system of human central-nervous-system myelin was investigated. Evidence obtained indicated the presence of at least two different phosphotransferase systems (cyclic nucleotide-dependent and -independent) in myelin, which were found to be firmly associated with the membrane. The cyclic AMP-dependent kinase of myelin and white-matter cytosol preferentially phosphorylated certain histone fractions and displayed only modest activity with basic protein as substrate. On the other hand, the cyclic nucleotide-independent system showed specificity toward basic protein. Its activity was not only dependent on Mg2+ but it was greatly enhanced by this bivalent cation. Whereas the cyclic nucleotide-dependent kinase could be extracted with buffers containing Triton X-100, the bivalent cation-regulated kinase resisted solubilization from myelin under these conditions.

scholarly journals Isolation and partial characterization of methylated arginines from the encephalitogenic basic protein of myelin

1971 ◽  
Vol 123 (1) ◽  
pp. 69-74 ◽  
Author(s):  
G. S. Baldwin ◽  
P. R. Carnegie
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ion Exchange ◽  
Human Brain ◽  
Conformational Changes ◽  
Basic Protein ◽  
The Central Nervous System ◽  
Derivatives Of ◽  
Exchange Behaviour

Two methylated derivatives of arginine were isolated from the encephalitogenic protein of myelin from the central nervous system. Evidence is presented for the proposed structures, ω-NN′-dimethylarginine and ω-N-monomethylarginine. In the encephalitogenic protein from human brain the proportion 1:6:10 for arginine:monomethylarginine:dimethylarginine residues was found to occur at position 107. Possible roles for the methylated arginine in conformational changes and altered ion-exchange behaviour are discussed.

scholarly journals Characterization of the Precursor Protein of the Non-Aβ Component of Senile Plaques (NACP) in the Human Central Nervous System

1996 ◽  
Vol 55 (8) ◽  
pp. 889-895 ◽  
Author(s):  
Michael C. Irizarry ◽  
Tae-Wan Kim ◽  
Megan MCNamara ◽  
Rudolph E. Tanzi ◽  
Julia M. George ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Senile Plaques ◽  
Precursor Protein ◽  
Human Central Nervous System

scholarly journals A phosphatidylinositol-linked peanut agglutinin-binding glycoprotein in central nervous system myelin and on oligodendrocytes.

1988 ◽  
Vol 106 (4) ◽  
pp. 1273-1279 ◽  
Author(s):  
D D Mikol ◽  
K Stefansson
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
White Matter ◽  
Gray Matter ◽  
Biochemical Characterization ◽  
Developmental Expression ◽  
Peanut Agglutinin ◽  
Human Central Nervous System ◽  
Binding Glycoprotein

Here we report the isolation and initial biochemical characterization of a 120-kD peanut agglutinin-binding glycoprotein from the adult human central nervous system (CNS), which is anchored to membranes through a phosphatidylinositol linkage. Myelin incubated with phosphatidylinositol-specific phospholipase C released the protein as a soluble polypeptide of 105 kD, which was isolated with peanut agglutinin-agarose affinity chromatography. The protein was found to be highly glycosylated. The protein appears to be confined to the CNS, where its developmental expression is region specific and parallels myelination. It is in greater quantity in white matter than in gray matter and it is in isolated human CNS myelin. Furthermore, ovine oligodendrocytes in culture contain the protein on their surfaces and release it into the supernatant as a soluble 105-kD form. We call this protein the oligodendrocyte-myelin protein.

scholarly journals Calcium- and cyclic AMP-regulated protein kinases of bovine central-nervous-system myelin

1984 ◽  
Vol 218 (3) ◽  
pp. 923-932 ◽  
Author(s):  
N C Wu ◽  
F Ahmad
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cyclic Amp ◽  
Substrate Specificity ◽  
Protein Kinases ◽  
Basic Protein ◽  
Phospholipases A2 ◽  
Dependent Protein ◽  
Myelin Fraction ◽  
Triton X

Bovine central-nervous-system myelin was found to contain both Ca2+-activated and cyclic AMP-dependent protein kinases. Each enzyme possesses unique solubility and substrate-specificity characteristics. The Ca2+-activated enzyme, like its substrate (basic protein), is probably deeply embedded in the neural membrane, whereas the cyclic AMP-dependent kinase appears to be much less tightly associated with myelin. Treatment of insoluble myelin fraction housing the Ca2+-activated kinase with phospholipase A2 and phospholipases A2 + C causes a decrease in its ability to become activated by Ca2+. This can be countered by phosphatidylserine and phosphatidylethanolamine. Whereas the activity of the Ca2+-activated membrane-associated kinase is inhibited by chlorpromazine, dibucaine, melittin and Triton X-100, it is activated by certain phorbol diesters (4 beta-phorbol 12-myristate 13-acetate, 4 beta-phorbol 12,13-didecanoate, 4 beta-phorbol 12,13-dibenzoate and 4 beta-phorbol 12,13-diacetate), which appear to exert this effect by lowering the concentration of Ca2+ normally required for the activation of this enzyme. Together these results suggest that the activation of the membrane-associated kinase by Ca2+ most probably requires certain lipids, perhaps those already present in the membrane.

Extracellular Cyclic Nucleotide Metabolism in the Human Central Nervous System

1980 ◽  
pp. 113-139 ◽  
Author(s):  
Benjamin Rix Brooks ◽  
James H. Wood ◽  
Maria Diaz ◽  
Carol Czerwinski ◽  
Leon P. Georges ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cyclic Nucleotide ◽  
Nucleotide Metabolism ◽  
Human Central Nervous System
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