인삼 Saponin이 양신장에서 정제한 Na+, K+-ATPase의 활성, 인산화 및 [3H]Ouabain결합에 미치는 영향

Effect of Ginseng Saponin on the Activity, Phosphorylation, [3H]Ouabain Binding of Purified Na+, K+-ATPase Isolated from the Outer Medulla of Sheep Kidney

The effects of ginseng saponin on the activity, phosphorylation, [3H]ouabain binding and light scattering (disruption) of purified Na+, K+-ATPase isolated from the outer medulla of sheep kidney were compared to those of gypsophila saponin, sodium dodecylsulfate (SDS), and Triton X-100 on the same parameters. Na+, K+-ATPase activity, phosphorylation, and [3H]ouabain binding were inhibited by ginseng saponin (triol>total>diol), SDS, or Triton X-100, but increased by gypsophila saponin. Low doses of ginseng saponin (3mcg saponin/mcg protein) decreased phosphorylation sites and ouabain binding site concentration (Bmax) without any change of turnover number and affinity for ouabain binding which were decreased by high dose of ginseng saponin (over 10mcg saponin/mcg protein), SDS or Triton X-100. On the other hand, gypsophila saponin increased the affinity without any change of Bmax for ouabain binding. Inhibition of Na+, K+-ATPase activity by ginseng saponin and SDS or Triton X-100 appeared before and after decrease in light scattering, respectively. These data suggest that ginseng saponins (total, diol, triol saponin) inhibit Na+, K+-ATPase activity by specific direct and general detergent action at low and high concentrations, respectively, and this inhibitory action of ginseng saponin to Na+, K+-ATPase is not general action of all saponins.