title: alpha-Tocopheryl succinate activates protein kinase C in cellular and cell-free systems.
abstract: The effect of alpha-tocopheryl succinate (TS) on protein kinase C (PKC) activity was examined. TS increased the auto-phosphorylation of PKC in vascular smooth muscle cells. Furthermore TS activated isolated PKC-like phorbol 12-myristate 13-acetate (PMA), although it was required at a significantly higher concentration than PMA for PKC activation. Molecular superimposition of the TS on PMA by computation suggested that TS took an active binding conformation to the PKC-like PMA, but that the conformational population was about 1/1.000. Consequently, we conclude that TS interacts directly with PKC, and activates it by taking an active conformation like PMA.
authors.affiliation: Faculty of Pharmaceutical Sciences, The University of Tokushima, Shomachi-1, Tokushima 770-8505, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Kogure
authors.forename: Susumu
authors.initials: S
authors.lastname: Hama
authors.forename: Satoru
authors.initials: S
authors.lastname: Goto
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Munakata
authors.forename: Akira
authors.initials: A
authors.lastname: Tokumura
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukuzawa
mesh_terms: D000818:Animals; D002474:Cell-Free System; D004789:Enzyme Activation / Q000187:drug effects; D008958:Models, Molecular; D008968:Molecular Conformation; D009131:Muscle, Smooth, Vascular / Q000201:enzymology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000737:chemistry / Q000494:pharmacology; D024505:Tocopherols; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D014810:Vitamin E; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D024505:Tocopherols