Degradation of Arachidonoyl‐Labeled Phosphatidylinositols by Brain Synaptosomes
- 1 February 1981
- journal article
- research article
- Published by Wiley in Journal of Neurochemistry
- Vol. 36 (2), 355-362
- https://doi.org/10.1111/j.1471-4159.1981.tb01602.x
Abstract
Incubation of synaptosomes from mouse brain together with 1-acyl-2-[14C]arachidonoyl-sn-glycerophosphoinositals (GPI) and sodium deoxycholate yielded diacylglycerols and free arachidonic acid. Diacylglycerol formation is attributed to hydrolysis by the diacyl-GPI-specific phospholipase C (EC 3.1.4.10), and this reaction requires sodium deoxycholate for optimal activity. The free arachidonic acid formed is attributed to hydrolysis of diacyl-GPI by phospholipase A (EC 3.1.1.5). Free fatty acid release was observed during incubation, even in the absence of bile salts, but this process was preferentially stimulated by sodium taurocholate. The release of fatty acids was not specific for diacyl-GPI, as similar release was obtained during incubation with other phosphoglycerides. In the presence of deoxycholate (2 mg/ml), the release of diacylglycerols was maximal at diacyl-GPI concentration .apprx. 1.0 mM. The free fatty acid release linear with respect to the substrate at least up to 1.4 mM. The rate of diacyglycerol release from diacyl-GPI was more rapid in the initial 30 min, whereas the free fatty acid release was linear with time up to 2 h. Under this incubation condition, Ca stimulated both types of hydrolytic action, although the concentration needed to achieve this stimulation was rather high. This type of labeled precursor is potentially useful for studies of the different modes of diacyl-GPI degradation by enzymes in brain subcellular membranes.Keywords
This publication has 31 references indexed in Scilit:
- METABOLISM OF ARACHIDONOYL PHOSPHOGLYCERIDES IN MOUSE BRAIN SUBCELLULAR FRACTIONSJournal of Neurochemistry, 1979
- ACYL GROUP COMPOSITION OF METABOLICALLY ACTIVE LIPIDS IN BRAIN: VARIANCES AMONG SUBCELLULAR FRACTIONS AND DURING POSTNATAL DEVELOPMENTJournal of Neurochemistry, 1978
- CHARACTERIZATION OF THE ENZYMIC TRANSFER OF ARACHIDONOYL GROUPS TO 1‐ACYL‐PHOSPHOGLYCERIDES IN MOUSE SYNAPTOSOME FRACTIONJournal of Neurochemistry, 1978
- Hydrolysis of endogenous diacyglycerol and monoacylglycerol by lipases in rat brain microsomesBiochemistry, 1977
- Hydrolysis of neutral glycerides by lipases of rat brain microsomesBiochimica et Biophysica Acta (BBA) - Lipids and Lipid Metabolism, 1976
- Inositol phospholipids and cell surface receptor functionBiochimica et Biophysica Acta (BBA) - Reviews on Biomembranes, 1975
- Phospholipase A1and A2Activities of Neuronal and Glial Cells of the Rabbit BrainHoppe-Seyler´s Zeitschrift für physiologische Chemie, 1973
- Subcellular Distribution and Kinetic Properties of Rat Brain Phospholipases A1and A2Hoppe-Seyler´s Zeitschrift für physiologische Chemie, 1973
- Composition of acyl groups in the neutral glycerides from mouse brainJournal of Neurochemistry, 1970
- The identification of lysophosphatidylinositol and its enzymic conversion to phosphatidylinositolBiochimica et Biophysica Acta, 1962