These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Purification and characterization of phosphatidylinositol synthase from human placenta.
    Author: Antonsson BE.
    Journal: Biochem J; 1994 Feb 01; 297 ( Pt 3)(Pt 3):517-22. PubMed ID: 8110188.
    Abstract:
    Phosphatidylinositol synthase (CDP-1,2-diacyl-sn-glycerol:myoinositol 3-phosphatidyltransferase, EC 2.7.8.11) was purified from the microsomal fraction of human placenta. The Triton X-100-extracted enzyme was purified 8300-fold over the microsomal fraction by affinity chromatography on CDP-diacylglycerol-Sepharose followed by ion-exchange chromatography on Mono Q. The purified enzyme had a molecular mass of 24,000 Da on SDS/PAGE. The enzyme had a pH optimum at 9.0, required Mn2+ or Mg2+, and was inhibited by Ca2+ and Zn2+. The Km for myo-inositol was determined to be 0.28 mM. Optimal activity was obtained at 0.2-0.4 mM CDP-diacylglycerol; higher concentrations of the lipid substrate inhibited the enzyme reaction. The enzyme was inhibited by nucleoside di- and tri-phosphates, Pi and PPi. CDP competitively inhibited the enzyme reaction with a Kis of 4 mM. The optimal temperature for the PtdIns synthase reaction was 50 degrees C.
    [Abstract] [Full Text] [Related] [New Search]