Evidence for a new inositol phospholipid in rat brain mitochondria

J. Bothmer, M. Markerink, J. Jolles

    Research output: Contribution to journalArticleAcademicpeer-review

    Abstract

    Phosphorylation of phosphatidylinositol (PI), phosphatidylinositol monophosphate (PIP) and diacylglycerol (DAG) was studied in rat brain cortex myelin, synaptosomal and mitochondrial fractions, with ATP as phosphate donor and endogenous phospholipids as substrate. All fractions had PI, PIP and DAG phosphorylating activity with their own characteristic subcellular distribution. However, in the mitochondrial fraction an unidentified lipid was phosphorylated, which had a slower Rf value than PIP2 on TLC. After hydrolysis of the polar head group of the lipid and separation on anion exchange columns, it appeared to be a phosphoinositide. The elution profile showed that it was not phosphatidylinositol trisphosphate, or a lyso-compound. The available evidence suggests that the unknown inositol phospholipid in rat brain mitochondria is a phosphatidylinositol 4,5-bisphosphate isomer, although the possibility of it being a glycosyl-phosphoinositide cannot be excluded.
    Original languageEnglish
    Pages (from-to)1077-1082
    Number of pages6
    JournalBiochemical and Biophysical Research Communications
    Volume187
    Issue number2
    DOIs
    Publication statusPublished - 1 Jan 1992

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