Johnson J L
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710.
Biofactors. 1988 Jul;1(2):153-5.
The oxidation of trimethylamine to trimethylamine N-oxide in animals is catalyzed by an enzyme which has not yet been fully characterized. The discovery that a bacterial enzyme catalyzing the reverse reaction, the reduction of trimethylamine N-oxide to trimethylamine, utilizes the molybdenum cofactor to carry out this function raised the possibility that trimethylamine oxidation may also be dependent on this cofactor. It was found, however, that liver tissue from tungsten-treated rats contained normal levels of trimethylamine oxidase. In addition, analysis of a urine sample from a patient with trimethylamine oxidase deficiency revealed the presence of normal levels of urothione, the degradation product of the molybdenum cofactor. These results suggest that trimethylamine oxidase is not a molybdoenzyme and that oxidation of trimethylamine proceeds by a mechanism which differs considerably from a simple reversal of trimethylamine N-oxide reduction.
动物体内将三甲胺氧化为三甲胺氮氧化物的过程由一种尚未完全表征的酶催化。一种催化逆反应（即三甲胺氮氧化物还原为三甲胺）的细菌酶利用钼辅因子来执行此功能，这一发现增加了三甲胺氧化也可能依赖于该辅因子的可能性。然而，发现来自经钨处理的大鼠的肝脏组织中三甲胺氧化酶水平正常。此外，对一名三甲胺氧化酶缺乏症患者的尿液样本分析显示，钼辅因子的降解产物尿硫酮水平正常。这些结果表明，三甲胺氧化酶不是一种钼酶，并且三甲胺的氧化过程通过一种与三甲胺氮氧化物还原的简单逆转有很大不同的机制进行。
