ISSN:
1573-4994
Keywords:
Cation binding
;
fluorescence decay
;
kinetics
;
binding constants
;
Na,K-ATPase
;
eosin Y
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract Time-resolved fluorescence and binding studies have been carried out on Na,K-ATPase in the presence of the fluorescent dye eosin Y to obtain thermodynamic and kinetic parameters for the interaction of the enzyme with different cations. Eosin Y binding is indicated by a 3 ns fluorescence decay process and is observed only in the presence of mono- and divalent cations. This type of cation binding is interpreted as a nonselective electrostatic interaction, with negatively charged groups of the enzyme providing a high-affinity eosin Y binding site. Eosin Y binding is observed only under conditions where the enzyme exists in the conformational state F1. The kinetic parameters of eosin Y binding have been determined employing stopped-flow fluorometry.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00732056
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