| Pre-steady-state phosphorylation and dephosphorylation of detergent-purified plasma-membrane Ca2+-ATPase. | |
| | |
MedLine Citation:
|
PMID: 11772407 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Pre-steady-state phosphorylation and dephosphorylation of purified and phospholipid-depleted plasma-membrane Ca(2+)-ATPase (PMCA) solubilized in the detergent polyoxyethylene 10 lauryl ether were studied at 25 degrees C. The time course of phosphorylation with ATP of the enzyme associated with Ca(2+), probably the true phosphorylation reaction, showed a fast phase (k(app) near 400 s(-1)) followed by a slow phase (k(app)=23 s(-1)). With asolectin or acidic phosphatidylinositol, the concentration of phosphoenzyme (EP) increased at as high a rate as before, passed through a maximum at 4 ms and stabilized at a steady level that was approx. half that without lipids. Calmodulin (CaM) did not change the rate of the fast phase, accelerated the slow phase (k(app)=93 s(-1)) and increased [EP] with small changes in the shape of the time course. Dephosphorylation was slow (k(app)=30 s(-1)) and insensitive to CaM. Asolectin accelerated dephosphorylation, which followed biexponential kinetics with fast (k(app)=220 s(-1)) and slow (k(app)=20 s(-1)) components. CaM stimulated the fast component by nearly 50%. The results show that the behaviour of the PMCA is complex, and suggest that acidic phospholipids and CaM activate PMCA through different mechanisms. Acceleration of dephosphorylation seems relevant during activation of the PMCA by acidic phospholipids. |
| | |
Authors:
|
Luis M Bredeston; Alcides F Rega |
Related Documents
:
|
2112367 - Occurrence of 9- and 13-keto-octadecadienoic acid in biological membranes oxygenated by... 2387677 - Lipids in human lipofuscin-enriched subcellular fractions of two age populations. compa... 6732827 - Enhanced n-acylation of palmitic acid in sphingomyelin of antibody-stimulated l cells. 16228647 - Evolving lipid vesicles in prebiotic hydrothermal environments. 20101327 - Topical treatment of melasma. 11050297 - Antinociceptive activity of ricinoleic acid, a capsaicin-like compound devoid of pungen... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: The Biochemical journal Volume: 361 ISSN: 0264-6021 ISO Abbreviation: Biochem. J. Publication Date: 2002 Jan |
Date Detail:
|
Created Date: 2002-01-04 Completed Date: 2002-02-14 Revised Date: 2009-11-18 |
Medline Journal Info:
|
Nlm Unique ID: 2984726R Medline TA: Biochem J Country: England |
Other Details:
|
Languages: eng Pagination: 355-61 Citation Subset: IM |
Affiliation:
|
Instituto de Química y Fisicoquímica Biológicas (Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Técnicas), Facultad de Farmacia y Bioquímica, Junín 956, 1113 Buenos Aires, Argentina. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adenosine Triphosphate
/
metabolism Calcium / metabolism Calcium-Transporting ATPases / metabolism* Calmodulin / metabolism Cell Membrane / enzymology Detergents / chemistry Kinetics Phosphatidylcholines Phosphatidylethanolamines / metabolism Phosphatidylinositols / metabolism Phospholipids / metabolism Phosphorylation Polyethylene Glycols / chemistry |
| Chemical | |
Reg. No./Substance:
|
0/Calmodulin; 0/Detergents; 0/Phosphatidylcholines; 0/Phosphatidylethanolamines; 0/Phosphatidylinositols; 0/Phospholipids; 0/Polyethylene Glycols; 56-65-5/Adenosine Triphosphate; 69279-91-0/asolectin; 7440-70-2/Calcium; EC 3.6.1.8/Calcium-Transporting ATPases |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Characterization of monoclonal antibodies against Escherichia coli core RNA polymerase.
Next Document: Metallothionein modulates lipopolysaccharide-stimulated tumour necrosis factor expression in mouse p...