Shirota F N, DeMaster E G, Nagasawa H T
Toxicol Lett. 1987 Jun;37(1):7-12. doi: 10.1016/0378-4274(87)90160-3.
Cyanide was detected as a product of cyanamide oxidation by bovine liver catalase in vitro under conditions that also produced an active aldehyde dehydrogenase (AlDH) inhibitor. Cyanide formation was directly related to both cyanamide and catalase concentrations and was also dependent on incubation time. The apparent Km for this reaction was 172 microM. Cyanide formation was blocked by ethanol, a known substrate for catalase Compound I. The toxic effects of cyanamide in the dog, a species with limited capacity to conjugate cyanamide by N-acetylation, may be causally related to enhancement of this catalase-mediated pathway for cyanamide metabolism.
在体外条件下,牛肝过氧化氢酶将氨基氰氧化会产生氰化物,同时还会产生一种活性醛脱氢酶(AlDH)抑制剂。氰化物的形成与氨基氰和过氧化氢酶的浓度直接相关,并且还取决于孵育时间。该反应的表观米氏常数为172微摩尔。氰化物的形成被乙醇阻断,乙醇是过氧化氢酶化合物I的已知底物。氨基氰对狗具有毒性作用,狗通过N - 乙酰化结合氨基氰的能力有限,其毒性作用可能与这种过氧化氢酶介导的氨基氰代谢途径的增强存在因果关系。