Department of Biochemistry, Lomonosov Moscow State University, Russia.
Biochemistry (Mosc). 2010 Oct;75(10):1281-4. doi: 10.1134/s000629791010010x.
Preparations of Na,K-ATPase from outer medulla of rabbit kidney purified in accordance with the method of P. L. Jorgensen were shown to contain as admixture a protease that moves with α-subunit (100 kDa) as a single protein band during one-dimensional SDS-PAGE. The electro-elution of proteins of this band from polyacrylamide gel results in the appearance of two protein fragments (67 and 55 kDa) that are stained with polyclonal antibodies against Na,K-ATPase α-subunit. Liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis showed that the neutral membrane-bound endopeptidase neprilysin is located in one protein band together with the Na,K-ATPase α-subunit. Addition of thiorphan, a specific inhibitor of neutral endopeptidase, eliminates proteolysis of the α-subunit. The data demonstrate that Na,K-ATPase α-subunit may be a natural target for neprilysin.
根据 P. L. Jorgensen 的方法纯化的兔肾外髓质 Na,K-ATPase 的制备物显示，其中含有一种蛋白酶，在一维 SDS-PAGE 中与 α-亚基（100 kDa）一起作为单一的蛋白质条带移动。从聚丙烯酰胺凝胶中电洗脱该条带中的蛋白质会产生两个蛋白质片段（67 和 55 kDa），它们被针对 Na,K-ATPase α-亚基的多克隆抗体染色。液相色谱/串联质谱 (LC/MS/MS) 分析表明，中性膜结合内肽酶 Neprilysin 与 Na,K-ATPase α-亚基位于同一蛋白质条带中。添加硫醇肽，一种中性内肽酶的特异性抑制剂，可消除 α-亚基的蛋白水解。这些数据表明，Na,K-ATPase α-亚基可能是 Neprilysin 的天然靶标。
