Angermüller S, Bruder G, Völkl A, Wesch H, Fahimi H D
Department of Anatomy, University of Heidelberg, Federal Republic of Germany.
Eur J Cell Biol. 1987 Dec;45(1):137-44.
The ultrastructural cytochemical localization of xanthine oxidase activity in rat liver was investigated by the cerium technique. The reaction product was found in the cytoplasm of endothelial cells in liver sinusoids and, in addition, in crystalline cores of peroxisomes of liver parenchymal cells. Xanthine oxidase was also present in peroxisomal cores of beef liver and kidney, but not in rat kidney peroxisomes, which lack crystalline cores. The localization in peroxisomal cores of rat liver was confirmed also biochemically using highly purified peroxisomal fractions and subfractions containing exclusively the crystalline cores. Moreover, high levels of molybdenum were found in isolated peroxisomal cores by atomic absorption spectroscopy, thus corroborating the association of the molybdenum-containing enzyme with the cores. Since urate oxidase is also present within the same compartment of peroxisomes, it is possible that the crystalline cores harbor a complex of several enzymes involved in the purine metabolism.
采用铈技术研究了大鼠肝脏中黄嘌呤氧化酶活性的超微结构细胞化学定位。在肝血窦内皮细胞的细胞质中发现了反应产物，此外，在肝实质细胞过氧化物酶体的晶体核心中也发现了反应产物。黄嘌呤氧化酶也存在于牛肉肝脏和肾脏的过氧化物酶体核心中，但不存在于大鼠肾脏过氧化物酶体中，大鼠肾脏过氧化物酶体缺乏晶体核心。使用高度纯化的过氧化物酶体组分和仅包含晶体核心的亚组分进行生化分析，也证实了大鼠肝脏过氧化物酶体核心中的定位。此外，通过原子吸收光谱法在分离的过氧化物酶体核心中发现了高水平的钼，从而证实了含钼酶与核心的关联。由于尿酸氧化酶也存在于过氧化物酶体的同一区室中，因此晶体核心可能含有参与嘌呤代谢的几种酶的复合物。
