인삼 사포닌이 개 심실 형질막의 K+-의존성 포스파타제 활성에 미치는 영향

Effect of Ginseng Saponins on K+-Dependent Phosphatase Activity of Dog Cardiac Sarcolemma

The effects of ginseng saponins, gypsophila saponin, sodium dodecyl sulfate(SDS), and Triton X-100 on membrane K+-dependent phosphatase activity which is lipid dependent and represents dephosphorylation step of the complete Na+, k+-ATPases reaction were investigated in this study to elucidate whether the effects of ginseng saponins are due to the detergent action, using sarcolemma enriched preparation isolated from dog ventricle. Na+, K+-ATPase and K+-dependent phosphatase activities of cardiac sarcolemma wee about 143mcmol Pi/mg protein/hr and 34mcmol p-nitrophenol/mg protein/hr, respectively. While ginseng saponins(triol>total>diol) inhibited K+-dependent phosphatase activity, gypsophila saponin, and low dose of SDS(0.4mcg/mcg protein), and Triton X-100 (0.6mcg/mcg protein) increased the enzyme activity, indicating disruptive effect of detergents on membrane barriers. The activating effect of low doses of Triton X-100 on membrane K+-dependent phosphatase appeared at concentration decreasing light scattering. However, the inhibitory effect of ginseng saponin apperared before a decrease in light scattering. Theses results suggest that low concentrations of ginseng saponins inhibit the membrane K+-dependent phosphatase by interacting directly with enzyme before membrane disruption.