Kojimahara N, Nakabayashi H, Shikata T, Esumi M
Medical Research Institute, Nihon University School of Medicine, Tokyo, Japan.
Liver. 1995 Jun;15(3):135-42. doi: 10.1111/j.1600-0676.1995.tb00660.x.
To examine the mechanism of decrease in serum ceruloplasmin (Cp) in Long-Evans Cinnamon (LEC) rats, a proposed model of Wilson's disease, we analyzed Cp products at the stages of transcription and translation. Northern blot analysis and immunoblot analysis showed that the level and the molecular size of Cp mRNA and protein in LEC rats were similar to those in control Long-Evans-Agouti (LEA) rats. However, the ferroxidase activity of Cp was significantly decreased in LEC rats. We separated serum Cp into two forms by native polyacrylamide gel electrophoresis with pH modification: one was a holo-Cp with copper and ferroxidase activity, and the other was an inactive apo-Cp without copper. Holo-Cp was the predominant form in LEA rats and normal humans, whereas apo-Cp was the major form in LEC rats and patients with Wilson's disease. The cosegregation of apo-Cp predominance with the disease in LEC rats was analyzed using backcross rats. Apo-Cp was dominant in 8 of 11 offspring with disease but in none of 19 normal offspring. These results indicate that a genetic disturbance of copper binding to apo-Cp may be closely associated with the pathogenesis in LEC rats, and probably in Wilson's disease.
为研究威尔逊病的一种拟用模型——长 Evans 肉桂色（LEC）大鼠血清铜蓝蛋白（Cp）降低的机制，我们分析了 Cp 在转录和翻译阶段的产物。Northern 印迹分析和免疫印迹分析表明，LEC 大鼠中 Cp mRNA 和蛋白质的水平及分子大小与对照长 Evans 刺鼠（LEA）大鼠相似。然而，LEC 大鼠中 Cp 的铁氧化酶活性显著降低。我们通过改变 pH 的非变性聚丙烯酰胺凝胶电泳将血清 Cp 分为两种形式：一种是具有铜和铁氧化酶活性的全铜蓝蛋白（holo-Cp），另一种是不含铜的无活性脱辅基铜蓝蛋白（apo-Cp）。全铜蓝蛋白是 LEA 大鼠和正常人中的主要形式，而脱辅基铜蓝蛋白是 LEC 大鼠和威尔逊病患者中的主要形式。利用回交大鼠分析了 LEC 大鼠中脱辅基铜蓝蛋白优势与疾病的共分离情况。脱辅基铜蓝蛋白在 11 只患病后代中的 8 只中占主导，但在 19 只正常后代中均未占主导。这些结果表明，铜与脱辅基铜蓝蛋白结合的遗传紊乱可能与 LEC 大鼠的发病机制密切相关，可能也与威尔逊病的发病机制有关。
