Studies on the anchorage of ATP diphosphohydrolase in synaptic plasma membranes from rat brain
| Autor: | Ana Maria Oliveira Battastini, Carla Denise Bonan, Tatiana Emanuelli, Letícia Scherer Koester, Renato Dutra Dias, João José Freitas Sarkis, Marcia Rosangela Wink |
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| Rok vydání: | 1998 |
| Předmět: |
Male
Octoxynol medicine.medical_treatment ATPase Detergents Synaptic Membranes Biochemistry Polyethylene Glycols Phosphoinositide Phospholipase C medicine Animals Centrifugation Rats Wistar chemistry.chemical_classification Protease Chromatography Phospholipase C biology Apyrase Phosphatidylinositol Diacylglycerol-Lyase Brain Membrane Proteins Cell Biology Rats Enzyme Membrane Membrane protein chemistry Solubility Type C Phospholipases biology.protein |
| Zdroj: | The international journal of biochemistrycell biology. 30(6) |
| ISSN: | 1357-2725 |
| Popis: | ATP diphosphohydrolases are described as ecto-enzymes in several tissues. In the present study, synaptic plasma membrane (SPM) was exposed to a series of agents used to distinguish between peripheral (hydrophilic), G-PI-anchored and transmembrane-polypeptide-anchored membrane proteins. These procedures included: (a) nondetergent extraction, (b) Triton X-114 phase partitioning, (c) phosphatidylinositol-specific phospholipase C (PI-PLC) extraction and (d) protease incubation. In cases (a), (c) and (d) the SPM was incubated with different agents and the ATPase–ADPase activities and the protein concentration was determined in the original sample, in the pellet and in the supernatant obtained after 100,000g centrifugation. In procedure (b), the SPM was solubilized in 1% triton X-114 and submitted to phase separation onto a sucrose cushion. The aqueous and detergent rich phases obtained by this treatment were assayed for ATPase–ADPase activities and protein determination. The results obtained suggest an intrinsic behaviour for ATP diphosphohydrolase since none of the nondetergent treatments was efficient in removing the enzyme from SPM. Moreover, ATPase and ADPase activities were recovered predominantly (>50%) in the detergent-rich phase obtained by Triton X-114 partitioning. The enzyme was not released by PI-PLC or proteases. These results indicate that the enzyme is not a GPI-anchored protein, but is probably deeply anchored on the plasma membrane in agreement with the amino acid sequence of the enzyme recently published. |
| Databáze: | OpenAIRE |
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