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.

Two-dimensional gel electrophoresis of human brain proteins. V. Non-equilibrium gel electrophoresis, with detection of a myelin basic protein mutation--MBL-Duarte.

1982 ◽  
Vol 28 (4) ◽  
pp. 813-818 ◽  
Author(s):  
D E Comings ◽  
A Pekkula-Flagan
Keyword(s):  
Human Brain ◽  
Myelin Basic Protein ◽  
Gel Electrophoresis ◽  
Basic Protein ◽  
Myelin Proteins ◽  
Two Dimensional Gel Electrophoresis ◽  
Brain Proteins ◽  
Basic Proteins ◽  
A Charge ◽  
Non Equilibrium

Abstract To examine the basic human brain proteins, we subjected 9 mmol/L urea extracts to non-equilibrium gel electrophoresis. The pattern observed differs distinctly from that with equilibrium gel electrophoresis. With this technique, the myelin proteins (myelin basic protein, proteolipids, and basic Wolfgram proteins) and many other unindentified major basic proteins can be demonstrated. The myelin basic proteins occur as two major polypeptides of different charge and slightly different molecular mass, indicating the action of at least two genes. The proteolipid proteins occur as a long series of charge isomers, suggesting multiple genes or extensive post-transcriptional modification. In one patient with schizophrenia, a charge-change mutation of the larger myelin basic protein (MBL) was observed and is termed "MBL-Duarte."

MYELIN BASIC PROTEIN IN FROZEN AND UNFROZEN BOVINE BRAIN: A STUDY OF AUTOLYTIC CHANGES IN SITU

1975 ◽  
Vol 25 (3) ◽  
pp. 193-195 ◽  
Author(s):  
K. A. Ansari ◽  
H. Hendrickson ◽  
A. A. Sinha ◽  
A. Rand
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Bovine Brain

Myelin basic protein inhibits histone-specific protein methylase I

1986 ◽  
Vol 874 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Gil-Hong Park ◽  
Latika P. Chanderkar ◽  
Woon Ki Paik ◽  
Sangduk Kim
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Specific Protein

Substrate specificity for myelin basic protein-specific protein methylase I

1990 ◽  
Vol 1039 (2) ◽  
pp. 142-148 ◽  
Author(s):  
Subrata K. Ghosh ◽  
Samiuddin K. Syed ◽  
Serena Jung ◽  
Woon Ki Paik ◽  
Sangduk Kim
Keyword(s):  
Substrate Specificity ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Specific Protein

scholarly journals Purification and kinetic mechanism of S-adenosylmethionine: myelin basic protein methyltransferase from bovine brain

1988 ◽  
Vol 250 (1) ◽  
pp. 221-226 ◽  
Author(s):  
P R Young ◽  
C M Waickus
Keyword(s):  
Myelin Basic Protein ◽  
Basic Protein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
High Specificity ◽  
Kinetic Mechanism ◽  
Bovine Brain ◽  
Tryptic Cleavage ◽  
Protein Methyltransferase

The enzyme S-adenosylmethionine (AdoMet): myelin basic protein (MBP) methyltransferase was purified 250-fold from bovine brain with an overall yield of 130%, relative to crude supernatant. The purification involves acid-base and (NH4)2SO4 precipitation, chromatography over Sephadex G-100 and DEAE-cellulose, followed by preparative isoelectric focusing. The enzyme has a pI of 5.60 +/- 0.05, and the Mr is estimated to be between 71,000 (from SDS/polyacrylamide-gel electrophoresis) and 74,500 (from gel filtration). The enzyme is stable at 37 degrees C for over 2 h, is stable frozen and does not require metal ions or reductants. The enzyme shows a high specificity for MBP and does not accept polyarginine as a substrate; F1 histone is methylated at 37% of the rate of MBP. Methylation occurs on an arginine residue in a single h.p.l.c.-resolvable peptide from the tryptic cleavage of MBP. Simple saturation kinetics are observed with respect to both substrates, with Km values of 18 microM and 32 microM for MBP and AdoMet respectively. The simplest kinetic mechanism that is consistent with the data requires ordered rapid-equilibrium binding, with AdoMet as the first substrate. The enzyme isolated in this work is different, both physically and kinetically, from the histone-specific arginine methyltransferases described by other workers. A new, simple, assay system for the methylation of MBP is described.

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