title: Partial characterization of the phosphotransferase system of human central-nervous-system myelin.
abstract: 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.
mesh_terms: D001921:Brain / Q000201:enzymology*; D002352:Carrier Proteins / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology; D000242:Cyclic AMP / Q000494:pharmacology; D006801:Humans; D066298:In Vitro Techniques; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008055:Lipids / Q000494:pharmacology; D009186:Myelin Sheath / Q000201:enzymology*; D017830:Octoxynol; D009994:Osmolar Concentration; D010766:Phosphorylation; D011092:Polyethylene Glycols / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism*; D012995:Solubility; D013379:Substrate Specificity
chemical_list: D002352:Carrier Proteins; D002413:Cations, Divalent; D047908:Intracellular Signaling Peptides and Proteins; D008055:Lipids; C015482:protein kinase modulator; D011092:Polyethylene Glycols; D017830:Octoxynol; D000242:Cyclic AMP; D011494:Protein Kinases