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Presence of Phospholipid‐ N ‐Methyltransferases and Base‐Exchange Enzymes in Rat Central Nervous System Axolemma‐Enriched Fractions
Author(s) -
Hattori Hiroshi,
Bansal Vinay S.,
Orihel Danka,
Kanfer Julian N.
Publication year - 1984
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1984.tb12838.x
Subject(s) - axolemma , biochemistry , enzyme , methyltransferase , phospholipid , sucrose , choline , chemistry , myelin , biology , central nervous system , membrane , endocrinology , methylation , gene
Rat CNS myelinated axons were fractionated by sucrose density gradient centrifugation with a zonal rotor. Fraction VI, obtained at 28–30% sucrose, appeared, on the basis of the presence of related marker enzymes, to be enriched in axolemma. Phospholipid‐ N ‐methyltransferases (PMTs) and base‐exchange enzymes were associated with fraction VI. PMT activity was significantly stimulated by the addition of either phosphatidylmonomethylethanolamine or phosphatidyldimethylethanolamine but the PMT activity of the homogenate or the myelinated axons was unresponsive. Recoveries of the ethanolamine, serine, and choline base‐exchange activities were 14.4%, 13.8%, and 3.4%, respectively, of that present in the myelinated axons. The myelin‐rich fraction obtained simultaneously seems contaminated with other membrane fractions.