二价阳离子对重组ADP、ATP交换的影响。

Influence of divalent cations on the reconstituted ADP, ATP exchange.

Krämer R

Biochim Biophys Acta. 1980 Oct 3;592(3):615-20. doi: 10.1016/0005-2728(80)90104-8.

Abstract

Divalent cations cause a decrease in the exchange activity of the reconstituted ADP,ATP translocator from beef heart mitochondria. This effect is due to complex formation with the adenine nucleotides. 2. It is confirmed that only the free nucleotides are transported. A possible competition of free adenine nucleotides and the Mg2+-complexes for the binding site at the carrier protein is excluded. 3. The stability constants (Kn) for the cation-nucleotide complexes are derived from these experiments. For Mg2+-ATP, Kn = 0.8 x 10(4) M-1 and for Mg2+-ADP, Kn = 0.8 x 10(3) M-1 is obtained. 4. The carrier system was reconstituted with the neutral phospholipids phosphatidylcholine and phosphatidylethanolamine. Interaction of the divalent cations with these phospholipids seem not to be important for the exchange suppression.

摘要

二价阳离子会使来自牛心线粒体的重组ADP、ATP转位酶的交换活性降低。这种效应是由于与腺嘌呤核苷酸形成复合物所致。2. 已证实只有游离核苷酸被转运。排除了游离腺嘌呤核苷酸和Mg2+复合物在载体蛋白结合位点上的可能竞争。3. 从这些实验中得出阳离子 - 核苷酸复合物的稳定常数（Kn）。对于Mg2+-ATP，Kn = 0.8×10(4) M-1，对于Mg2+-ADP，Kn = 0.8×10(3) M-1。4. 载体系统用中性磷脂磷脂酰胆碱和磷脂酰乙醇胺进行了重组。二价阳离子与这些磷脂的相互作用似乎对交换抑制并不重要。