Hall C, Ruoho A
Proc Natl Acad Sci U S A. 1980 Aug;77(8):4529-33. doi: 10.1073/pnas.77.8.4529.
4"'-Diazomalonyldigitoxin and its isomer, 3"'-diazomalonyldigitoxin, have been synthesized at high specific radioactivity and used as photolabels for the Na,K-ATPase (ATP phosphohydrolase, EC 3.6.1.3) purified from Electrophorus electricus. Photoaffinity labeling experiments using both type I and type II complexes of enzyme with both photolabels showed ouabain-protectable labeling of the alpha as well as the beta subunit. These data suggest that, in the purified eel enzyme, the alpha and beta subunits are in intimate contact, at least in the region of the third digitoxose of the "sugar-specific" binding site.
4"'-重氮丙二酰洋地黄毒苷及其异构体3"'-重氮丙二酰洋地黄毒苷已被高比放射性合成,并用作从电鳗(Electrophorus electricus)纯化的钠钾ATP酶(ATP磷酸水解酶,EC 3.6.1.3)的光标记物。使用酶的I型和II型复合物以及两种光标记物进行的光亲和标记实验表明,哇巴因可保护α亚基和β亚基的标记。这些数据表明,在纯化的鳗鱼酶中,α亚基和β亚基至少在“糖特异性”结合位点的第三个洋地黄毒糖区域紧密接触。