Rafii F, Cerniglia C E
National Center for Toxicological Research, U.S. Food and Drug Administration, Jefferson, Arkansas 72079, USA.
Environ Health Perspect. 1995 Jun;103 Suppl 5(Suppl 5):17-9. doi: 10.1289/ehp.95103s417.
Several anaerobic bacteria from the human intestinal tract are capable of reducing azo dyes and nitropolycyclic aromatic hydrocarbons to the corresponding aromatic amines with enzymes that have azoreductase and nitroreductase activities. The majority of bacteria with these activities belong to the genera Clostridium and Eubacterium. The azoreductases and nitroreductases from three Clostridium strains and one Eubacterium strain were studied. Both enzymes were produced constitutively in each of the bacteria; the enzymes from various bacteria had different electrophoretic mobilities. The azoreductases from all of the bacteria had immunological homology, as was evident from the cross-reactivity of an antibody raised against the azoreductase of C. perfringens with azoreductases from other bacteria. Comparison of azoreductases and nitroreductases showed that they both had identical electrophoretic mobilities on polyacrylamide gels and reacted with the antibody against the azoreductase from C. perfringens. Furthermore, the nitroaromatic compounds competitively inhibited the azoreductase activity. The data indicate that the reduction of both nitroaromatic compounds and azo dyes may be carried out by the same enzyme, which is possibly a flavin adenine dinucleotide dehydrogenase that is synthesized throughout the cell and not associated with any organized subcellular structure.
来自人类肠道的几种厌氧细菌能够利用具有偶氮还原酶和硝基还原酶活性的酶将偶氮染料和硝基多环芳烃还原为相应的芳香胺。大多数具有这些活性的细菌属于梭菌属和真杆菌属。对三株梭菌和一株真杆菌的偶氮还原酶和硝基还原酶进行了研究。这两种酶在每种细菌中都是组成型产生的；来自不同细菌的酶具有不同的电泳迁移率。所有细菌的偶氮还原酶都具有免疫同源性，这从针对产气荚膜梭菌偶氮还原酶产生的抗体与其他细菌的偶氮还原酶的交叉反应中可以明显看出。偶氮还原酶和硝基还原酶的比较表明，它们在聚丙烯酰胺凝胶上具有相同的电泳迁移率，并且与针对产气荚膜梭菌偶氮还原酶的抗体发生反应。此外，硝基芳香化合物竞争性抑制偶氮还原酶活性。数据表明，硝基芳香化合物和偶氮染料的还原可能由同一种酶进行，这种酶可能是一种黄素腺嘌呤二核苷酸脱氢酶，它在整个细胞中合成，不与任何有组织的亚细胞结构相关。
