Smyser B P, Hodgson E
Biochem Pharmacol. 1985 Apr 15;34(8):1145-50. doi: 10.1016/0006-2952(85)90487-3.
Oxidative desulfuration of phosphonate insecticides such as fonofos (S-phenyl ethyl ethylphosphonodithioate) and its analogs is catalyzed by pig liver microsomal FAD-containing monooxygenase, although desulfuration of phosphorodithioates, such as parathion, is not. Substitution of an alkyl group for the remaining alkoxy group, as in S-phenyl diethylphosphinodithioate, did not increase its oxidation rate. Diethylphenylphosphine sulfide, containing 3 phosphorus-carbon bonds, was actually a poorer substrate than fonofos. Replacement of the S-phenyl group of fonofos with an O-phenyl group increased the Km value above the solubility limit. Trivalent phosphorus-containing compounds were also excellent substrates for this enzyme. Diethylphenylphosphine had a Km value lower than 2.5 microM. Diethyl phenylphosphonite also appeared to be an excellent substrate but its rapid nonenzymatic hydrolysis and/or oxidation precluded accurate Km determinations. Stoichiometry studies with diethylphenylphosphine and its sulfide showed that O2 and NADPH consumption were approximately equal to the substrate consumed. The major metabolite of both diethylphenylphosphine and its sulfide was the phosphine oxide. These results show that microsomal FAD-containing monooxygenase of pig liver has activity as a phosphorus-oxidase, in addition to its well characterized nitrogen- and sulfur-oxidase roles.
猪肝微粒体含黄素腺嘌呤二核苷酸的单加氧酶可催化膦酸酯类杀虫剂如地虫硫磷（S-苯基乙基乙基硫代磷酰二硫酯）及其类似物的氧化脱硫反应，而对硫代磷酸酯类如对硫磷则无此作用。用烷基取代剩余的烷氧基，如在S-苯基二乙基硫代磷酰二硫酯中，并不会提高其氧化速率。含3个磷-碳键的二乙苯基膦硫化物实际上是比地虫硫磷更差的底物。将地虫硫磷的S-苯基用O-苯基取代会使米氏常数高于溶解度极限。含三价磷的化合物也是该酶的优良底物。二乙苯基膦的米氏常数低于2.5微摩尔。二乙基亚磷酸苯酯似乎也是优良底物，但其快速的非酶促水解和/或氧化妨碍了准确的米氏常数测定。对二乙苯基膦及其硫化物的化学计量学研究表明，氧气和烟酰胺腺嘌呤二核苷酸磷酸的消耗大致与底物消耗相当。二乙苯基膦及其硫化物的主要代谢产物都是氧化膦。这些结果表明，猪肝微粒体含黄素腺嘌呤二核苷酸的单加氧酶除了具有其已充分表征的氮和硫氧化酶作用外，还具有磷氧化酶的活性。
