Kumari K, Ansari N H, Saxena M, Awasthi Y C, Srivastava S K
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston 77555.
Exp Eye Res. 1993 Aug;57(2):243-7. doi: 10.1006/exer.1993.1120.
Dinitrophenyl S-glutathione (Dnp-SG) ATPase which catalyses the hydrolysis of ATP in the presence of GSH-conjugates has been implicated previously in the transport of these conjugates. In the present studies we demonstrate that Dnp-SG ATPase is present in bovine lens epithelium and cortex. The specific activity per mg membrane protein was found to be 75-fold higher in the epithelium as compared to the cortex. No enzyme was detected in the nuclear region of the lens. Dnp-SG ATPase was purified from bovine lens epithelium and cortex using Dnp-SG-Sepharose 6MB affinity chromatography. The partially purified Dnp-SG ATPase had two distinct Km values, 120 microM and 1.0 mM. The antibodies raised against human erythrocyte Dnp-SG ATPase cross-reacted with the bovine lens epithelium Dnp-SG ATPase which was identified by Western blot as a band corresponding to an approximate M(r) value of 80,000 Da.
二硝基苯基-S-谷胱甘肽（Dnp-SG）ATP酶在谷胱甘肽共轭物存在的情况下催化ATP水解，此前一直被认为与这些共轭物的转运有关。在本研究中，我们证明Dnp-SG ATP酶存在于牛晶状体上皮和皮质中。每毫克膜蛋白的比活性在上皮中比在皮质中高75倍。在晶状体的核区域未检测到该酶。使用Dnp-SG-Sepharose 6MB亲和层析从牛晶状体上皮和皮质中纯化Dnp-SG ATP酶。部分纯化的Dnp-SG ATP酶有两个不同的Km值，分别为120微摩尔和1.0毫摩尔。针对人红细胞Dnp-SG ATP酶产生的抗体与牛晶状体上皮Dnp-SG ATP酶发生交叉反应，通过蛋白质印迹法鉴定该酶为一条对应于约80,000道尔顿分子量的条带。
