Dixon N E, Blakeley R L, Zerner B
Can J Biochem. 1980 Jun;58(6):469-73. doi: 10.1139/o80-062.
A simple and inexpensive procedure for determination of microgram quantities of metal ions in proteins is described and tested with nickel and iron. The method involves (a) dry ashing in an oxygen atmosphere at 450-460 degrees C in Pyrex vessels, (b) conversion of the metal oxides or other compounds to readily soluble species, and (c) spectrophotometric analysis. An improved procedure for the direct spectrophotometric determination of nickel using dimethylglyoxime is accurate to +/- 2% or better with samples of 1-5 microgram of nickel. These techniques were used to determine that the nickel content of freshly prepared jack bean urease in 2.00 +/- 0.12 g-at./96 600 g protein. The corresponds to 2.0 nickel ions per subunit. This result was confirmed by atomic absorption analysis, which also showed that calcium, manganese, cobalt, and iron are not present in significant amounts in urease.
本文描述了一种简单且成本低廉的方法，用于测定蛋白质中微克量的金属离子，并以镍和铁进行了测试。该方法包括：（a）在派热克斯玻璃容器中于450 - 460摄氏度的氧气氛围中进行干灰化；（b）将金属氧化物或其他化合物转化为易溶物质；（c）进行分光光度分析。使用丁二酮肟直接分光光度法测定镍的改进方法，对于1 - 5微克镍的样品，准确度可达±2%或更高。这些技术用于测定新鲜制备的刀豆脲酶中镍含量为2.00±0.12克原子/96600克蛋白质。这相当于每个亚基有2.0个镍离子。原子吸收分析证实了该结果，同时该分析还表明脲酶中钙、锰、钴和铁的含量不高。
