Britton L, Fridovich I
J Bacteriol. 1977 Sep;131(3):815-20. doi: 10.1128/jb.131.3.815-820.1977.
All of the superoxide dismutase isozymes of Escherichia coli have been shown to occur in the cell matrix, and none have been found in the periplasm. This was the case with both E. coli B and E. coli K-12, whether grown on a low phosphate medium or on a Trypticase soy-yeast extract medium. Alkaline phosphatase was used as a marker of the periplasm; adenosine deaminase and glucose 6-phosphate dehydrogenase were used as matrix markers, and consistent results were obtained by osmotic shock, spheroplast formation, and use of a diazonium salt that penetrates the periplasm but cannot cross the plasma membrane. A previous report that the iron-containing superoxide dismutase of E. coli is a periplasmic enzyme is now seen to have been in error.
已证明大肠杆菌的所有超氧化物歧化酶同工酶都存在于细胞基质中，而在周质中未发现。无论是大肠杆菌B还是大肠杆菌K-12，无论在低磷酸盐培养基上还是在胰蛋白酶大豆酵母提取物培养基上生长，都是如此。碱性磷酸酶用作周质的标志物；腺苷脱氨酶和葡萄糖6-磷酸脱氢酶用作基质标志物，通过渗透休克、原生质球形成以及使用可穿透周质但不能穿过质膜的重氮盐获得了一致的结果。先前关于大肠杆菌含铁超氧化物歧化酶是一种周质酶的报道现在被认为是错误的。
