Landis W G, Haley D M, Haley M V, Johnson D W, Durst H D, Savage R E
J Appl Toxicol. 1987 Feb;7(1):35-41. doi: 10.1002/jat.2550070107.
Recently it has been found that homogenates of Tetrahymena thermophila can hydrolyze the potent acetylcholinesterase inhibitors O,O-diisopropylphosphofluoridate (DFP) and O-1,2,2-trimethylpropylmethylphosphonofluoridate (soman). Upon purification of the DFP hydrolyzing activity 10-fold it had been noted that the soman hydrolyzing activity increased only 2-3 fold. Treatment with manganous ion and comparison of the soman and DFP hydrolysis rates of the homogenate indicated that a mixture of the squid-type and Mazur-type DFPases may be present. Subsequent purification of the enzymatic activities within the Tetrahymena-homogenate demonstrated that there are at least five functioning proteins of molecular weights 67,000 to 96,000. None are directly homologous to the DFPases found in hog kidney or squid. The enzymatic activities are designated DFPase-1 through DFPase-5. A hypothesis is presented that the functions of DFPases are in the normal metabolism of organophosphates naturally synthesized by T. thermophila.
最近发现，嗜热四膜虫的匀浆能够水解强效乙酰胆碱酯酶抑制剂O,O -二异丙基磷酰氟化物（DFP）和O - 1,2,2 -三甲基丙基甲基磷酰氟化物（梭曼）。在将DFP水解活性纯化10倍后，发现梭曼水解活性仅增加了2 - 3倍。用锰离子处理并比较匀浆中梭曼和DFP的水解速率表明，可能存在鱿鱼型和马祖尔型DFP酶的混合物。随后对嗜热四膜虫匀浆中的酶活性进行纯化，结果表明至少存在五种分子量在67,000至96,000之间的起作用的蛋白质。它们与在猪肾或鱿鱼中发现的DFP酶均无直接同源性。这些酶活性被命名为DFP酶-1至DFP酶-5。本文提出了一个假设，即DFP酶的功能在于嗜热四膜虫天然合成的有机磷酸酯的正常代谢过程中。
