| E2P phosphoforms of Na,K-ATPase. I. Comparison of phosphointermediates formed from ATP and Pi by their reactivity toward hydroxylamine and vanadate. | |
| | |
MedLine Citation:
|
PMID: 9753450 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
The properties of Na,K-ATPase phosphoenzymes formed either from ATP in the presence of Mg2+ and Na+ or from Pi in the absence of alkali cations were investigated by biochemical methods and spectrofluorometry employing the styryl dye RH421. We characterized the phosphoenzyme species by their reaction to N-methyl hydroxylamine, which attacks specifically the protein-phosphate bond. We studied reactions of the phospho- and dephospho-enzymes with vanadate, which is a transition-state analogue of phosphate in this enzyme. On the basis of substantial differences in the properties of the phosphoenzyme species formed either from ATP or Pi, especially in their reactivity to N-methyl hydroxylamine, it is suggested that the two phosphoenzyme species are two subconformations of the E2P phosphoform. Analysis of the RH421 fluorescence responses under a variety of experimental conditions and comparing different enzyme sources suggested that the increase of RH421 fluorescence induced by inorganic phosphate in the absence of alkali cations is associated with the formation of the covalent acyl-phosphate bond. |
| | |
Authors:
|
N U Fedosova; F Cornelius; I Klodos |
Publication Detail:
|
Type: Comparative Study; Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
|
Title: Biochemistry Volume: 37 ISSN: 0006-2960 ISO Abbreviation: Biochemistry Publication Date: 1998 Sep |
Date Detail:
|
Created Date: 1998-10-28 Completed Date: 1998-10-28 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0370623 Medline TA: Biochemistry Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 13634-42 Citation Subset: IM |
Affiliation:
|
Department of Biophysics, University of Aarhus, Denmark. nf@biophys.au.dk |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adenosine Triphosphate
/
metabolism* Animals Binding, Competitive Enzyme Activation / drug effects Fluorescent Dyes Hydroxylamines / metabolism*, pharmacology Phosphates / metabolism* Phosphoproteins / antagonists & inhibitors, chemistry, metabolism* Phosphorylation / drug effects Pyridinium Compounds / metabolism Sharks Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors, chemistry, metabolism* Spectrometry, Fluorescence Styrenes / metabolism Swine Vanadates / metabolism*, pharmacology |
| Chemical | |
Reg. No./Substance:
|
0/Fluorescent Dyes; 0/Hydroxylamines; 0/Phosphates; 0/Phosphoproteins; 0/Pyridinium Compounds; 0/Styrenes; 0/Vanadates; 107610-19-5/RH 421; 56-65-5/Adenosine Triphosphate; 593-77-1/N-methylhydroxylamine; EC 3.6.3.9/Sodium-Potassium-Exchanging ATPase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Modulation of the positional specificity of lecithin-cholesterol acyltransferase by the acyl group c...
Next Document: A polar octapeptide fused to the N-terminal fusion peptide solubilizes the influenza virus HA2 subun...