Jiang S S, Yang S J, Kuo S Y, Pan R L
Department of Life Science, College of Life Science, National Tsing Hua University, Hsin Chu, Taiwan.
FEBS Lett. 2000 Feb 25;468(2-3):211-4. doi: 10.1016/s0014-5793(00)01215-1.
Radiation inactivation analysis was employed to determine the functional masses of enzymatic activity and proton translocation of H(+)-pyrophosphatase from submitochondrial particles of etiolated mung bean seedlings. The activities of H(+)-pyrophosphatase decayed as a simple exponential function with respect to radiation dosage. D(37) values of 6.9+/-0.3 and 7.5+/-0.5 Mrad were obtained for pyrophosphate hydrolysis and its associated proton translocation, yielding molecular masses of 170+/-7 and 156+/-11 kDa, respectively. In the presence of valinomycin and 50 mM KCl, the functional size of H(+)-pyrophosphatase of tonoplast was decreased, while that of submitochondrial particles remained the same, indicating that they are two distinct types of proton pump using PP(i) as their energy source.
采用辐射失活分析来测定黄化绿豆幼苗亚线粒体颗粒中H(+)-焦磷酸酶的酶活性功能质量和质子转运功能质量。H(+)-焦磷酸酶的活性随辐射剂量呈简单指数函数衰减。焦磷酸水解及其相关质子转运的D(37)值分别为6.9±0.3和7.5±0.5兆拉德，相应的分子质量分别为170±7和156±11 kDa。在缬氨霉素和50 mM KCl存在的情况下，液泡膜H(+)-焦磷酸酶的功能大小减小，而亚线粒体颗粒的功能大小保持不变，这表明它们是以焦磷酸（PP(i)）为能量来源的两种不同类型的质子泵。
