人体红细胞中Li⁺与Mg²⁺对ATP的竞争。一项³¹P核磁共振与光谱学研究。

Competition between Li+ and Mg2+ for ATP in human erythrocytes. A 31P NMR and optical spectroscopy study.

作者信息

Ramasamy R, de Freitas D M

机构信息

Department of Chemistry, Loyola University of Chicago, IL 60626.

出版信息

FEBS Lett. 1989 Feb 13;244(1):223-6. doi: 10.1016/0014-5793(89)81197-4.

DOI:10.1016/0014-5793(89)81197-4

PMID:2924906

Abstract

We have investigated the influence of Li+ on free intracellular Mg2+ concentration in human erythrocytes by 31P NMR and optical absorbance spectroscopies. In red cells loaded with 3 mM intracellular Li+, the chemical shift separation between the alpha- and beta-phosphate resonances of MgATP2- was approx. 0.9 ppm larger than that observed in Li+-free red cells. By analyzing the interaction of each red cell component with Mg2+ and Li+, we found that Mg2+ is displaced in part from MgATP2- upon addition of Li+ and that the released Mg2+ is bound to the red cell membrane causing an overall decrease in free intracellular Mg2+ concentration.

摘要

我们通过31P核磁共振和光吸收光谱法研究了Li+对人红细胞内游离Mg2+浓度的影响。在细胞内加载3 mM Li+的红细胞中，MgATP2-的α-和β-磷酸共振之间的化学位移分离比在无Li+的红细胞中观察到的约大0.9 ppm。通过分析每个红细胞成分与Mg2+和Li+的相互作用，我们发现加入Li+后，Mg2+部分地从MgATP2-中被取代，并且释放的Mg2+与红细胞膜结合，导致细胞内游离Mg2+浓度总体下降。