Berthold D A, Fluke D J, Siedow J N
Department of Botany, Duke University, Durham, NC 27706.
Biochem J. 1988 May 15;252(1):73-7. doi: 10.1042/bj2520073.
The functional molecular mass of the cyanide-resistant salicylhydroxamate-sensitive duroquinol oxidase activity from Sympocarpus foetidus (skunk cabbage) and Sauromatum guttatum spadix mitochondria was determined by radiation-inactivation analysis. The functional molecular mass for the oxidase activity was found to be 26,700 Da for skunk cabbage and 29,700 Da for Sauromatum guttatum mitochondria frozen at -70 degrees C. Irradiation of dried mitochondrial samples resulted in a larger target size of 38,000 Da, and in some cases, a stimulation of activity at low dose of radiation. The functional molecular mass of cytochrome c oxidase activity from skunk-cabbage and bovine heart mitochondria was also investigated. Dried and frozen mitochondrial samples from both species yielded similar target sizes, in the range 70,900-73,400 Da. Purified bovine heart cytochrome c oxidase was also irradiated, and yielded a functional molecular mass of 66,400 Da. The target size of cytochrome c oxidase agrees with literature values insofar as the target size is considerably smaller than the molecular mass of the entire complex.
通过辐射失活分析测定了臭菘和疣柄魔芋 spadix 线粒体中抗氰化物、水杨羟肟酸敏感的对苯二酚氧化酶活性的功能分子质量。对于在 -70℃ 冷冻的臭菘线粒体,该氧化酶活性的功能分子质量为 26,700 Da,对于疣柄魔芋线粒体则为 29,700 Da。干燥线粒体样品的辐照导致更大的靶标大小,为 38,000 Da,并且在某些情况下,低剂量辐射会刺激活性。还研究了臭菘和牛心线粒体中细胞色素 c 氧化酶活性的功能分子质量。来自这两个物种的干燥和冷冻线粒体样品产生了相似的靶标大小,范围在 70,900 - 73,400 Da 之间。纯化的牛心细胞色素 c 氧化酶也进行了辐照,其功能分子质量为 66,400 Da。细胞色素 c 氧化酶的靶标大小与文献值一致,因为靶标大小明显小于整个复合物的分子质量。