Schmalzing G, Kröner S, Passow H
Max-Planck-Institut für Biophysik, Frankfurt, Federal Republic of Germany.
Biochem J. 1989 Jun 1;260(2):395-9. doi: 10.1042/bj2600395.
Ouabain binding was studied in Xenopus laevis oocytes permeabilized by detergents. The behaviour of markers showed that 10 microM-digitonin selectively disrupts the plasma membrane. In the presence of ATP, oocytes permeabilized at 10 microM-digitonin bound no more ouabain molecules than were required to abolish active 86Rb+ uptake in the intact cells. However, the ouabain binding capacity increased approx. 2-fold when inner membranes were disrupted by SDS or excess digitonin, as judged from the accompanying release of the lysosomal marker beta-hexosaminidase. The results suggest that oocytes have a large internal pool of functional sodium pumps.
在经去污剂通透处理的非洲爪蟾卵母细胞中研究哇巴因结合情况。标志物的行为表明，10微摩尔的洋地黄皂苷能选择性地破坏质膜。在ATP存在的情况下，经10微摩尔洋地黄皂苷通透处理的卵母细胞结合的哇巴因分子数量，并不比消除完整细胞中活性86Rb+摄取所需的数量更多。然而，根据溶酶体标志物β-己糖胺酶的伴随释放判断，当内膜被十二烷基硫酸钠（SDS）或过量洋地黄皂苷破坏时，哇巴因结合能力增加了约2倍。结果表明，卵母细胞有大量功能性钠泵的内部储备。
