Johnson J L, Waud W R, Rajagopalan K V, Duran M, Beemer F A, Wadman S K
Proc Natl Acad Sci U S A. 1980 Jun;77(6):3715-9. doi: 10.1073/pnas.77.6.3715.
A patient suffering from a combined deficiency of sulfite oxidase (sulfite dehydrogenase; sulfite:ferricytochrome c oxidoreductase, EC 1.8.2.1) and xanthine dehydrogenase (xanthine:NAD+ oxidoreductase, EC 1.2.1.37) is described. The patient displays severe neurological abnormalities, dislocated ocular lenses, and mental retardation. Urinary excretion of sulfite, thiosulfate, S-sulfocysteine, taurine, hypoxanthine, and xanthine is increased in this individual, while sulfate and urate levels are drastically reduced. The metabolic defect responsible for loss of both enzyme activities appears to be at the level of the molybdenum cofactor common to the two enzymes. Immunological examination of a biopsy sample of liver tissue revealed the presence of the xanthine dehydrogenase protein in near normal amounts. Sulfite oxidase apoprotein was not detected by a variety of immunological techniques. The plasma molybdenum concentration was normal; however, hepatic content of molybdenum and the storage pool of active molybdenum cofactor present in normal livers were below the limits of detection. Fibroblasts cultured from this patient failed to express sulfite oxidase protein or activity, whereas those from the parents and healthy brother of the patient expressed normal levels of this enzyme.
本文描述了一名患有亚硫酸盐氧化酶（亚硫酸盐脱氢酶；亚硫酸盐：铁细胞色素c氧化还原酶，EC 1.8.2.1）和黄嘌呤脱氢酶（黄嘌呤：NAD+氧化还原酶，EC 1.2.1.37）联合缺乏症的患者。该患者表现出严重的神经异常、晶状体脱位和智力发育迟缓。该个体尿液中亚硫酸盐、硫代硫酸盐、S-磺基半胱氨酸、牛磺酸、次黄嘌呤和黄嘌呤的排泄增加，而硫酸盐和尿酸水平则大幅降低。导致两种酶活性丧失的代谢缺陷似乎发生在这两种酶共有的钼辅因子水平。对肝脏组织活检样本的免疫学检查显示，黄嘌呤脱氢酶蛋白的含量接近正常。通过多种免疫学技术均未检测到亚硫酸盐氧化酶脱辅基蛋白。血浆钼浓度正常；然而，肝脏中的钼含量以及正常肝脏中活性钼辅因子的储存池低于检测限。从该患者培养的成纤维细胞未能表达亚硫酸盐氧化酶蛋白或活性，而来自患者父母和健康兄弟的成纤维细胞则表达正常水平的这种酶。
