Anion interactions with Na,K-ATPase: simultaneous binding of nitrate and eosin

被引：2

作者：

Esmann, M ^{[1
]}

Fedosova, NU ^{[1
]}

机构：

[1] Univ Aarhus, Dept Biophys, Aarhus 8000, Denmark

来源：

EUROPEAN BIOPHYSICS JOURNAL WITH BIOPHYSICS LETTERS | 2004年 / 33卷 / 08期

关键词：

nucleotide binding affinity; Na; K-ATPase; anion interactions; simultaneous anion binding;

D O I：

10.1007/s00249-004-0411-6

中图分类号：

Q6 [生物物理学];

学科分类号：

071011 ;

摘要：

Nucleotide binding affinity to Na,K-ATPase is reduced by a number of anions such as nitrate and perchlorate in comparison with affinity in the presence of chloride (all with sodium as the cation). The reduction correlates with the position of these anions in the Hofmeister series. Transient kinetic experiments using the fluorescent dye eosin-which binds to the nucleotide site of the Na,K-ATPase-show that simultaneous anion binding.. exemplified with nitrate, and eosin binding is possible. The effect of nitrate on eosin binding is reflected in a decreased bindin-rate constant and an increased dissociation rate constant, leading to a decreased equilibrium binding constant for eosin. Since eosin binding is analogous with nucleotide binding to Na,K-ATPase, the results suggest the simultaneous presence of nucleotide and anion binding sites.

引用

页码：683 / 690

页数：8

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