National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashihiroshima, Hiroshima, 739-0046, Japan.
Appl Microbiol Biotechnol. 2022 May;106(9-10):3431-3438. doi: 10.1007/s00253-022-11953-8. Epub 2022 May 10.
Urethanase (EC 3.5.1.75) can reduce ethyl carbamate (EC), a group 2A carcinogen found in foods and liquor. However, it is not yet commercially available. Urethanase has been detected as an intracellular enzyme from yeast, filamentous fungi, and bacteria. Based on the most recent progress in the sequence analysis of this enzyme, it was observed that amidase-type enzyme can degrade EC. All five enzymes had highly conserved sequences of amidase signature family, and their molecular masses were in the range of 52-62 kDa. The enzymes of Candida parapsilosis and Aspergillus oryzae formed a homotetramer, and that of Rhodococcus equi strain TB-60 existed as a monomer. Most urethanases exhibited amidase activity, and those of C. parapsilosis and A. oryzae also demonstrated high activity against acrylamide, which is a group 2A carcinogen. It was recently reported that urease and esterase also exhibited urethanase activity. Although research on the enzymatic degradation of EC has been very limited, recently some sequences of EC-degrading enzyme have been elucidated, and it is anticipated that new enzymes would be developed and applied into practical use. KEY POINTS: • Recently, some urethanase sequences have been elucidated • The amino acid residues that formed the catalytic triad were conserved • Urethanase shows amidase activity and can also degrade acrylamide.
尿烷酶（EC 3.5.1.75）可以降低乙基碳酸酯（EC），这是一种存在于食品和酒类中的 2A 类致癌物质。然而，它目前还没有商业化。尿烷酶已被检测为来自酵母、丝状真菌和细菌的细胞内酶。根据该酶最近在序列分析方面的进展，发现酰胺酶型酶可以降解 EC。这 5 种酶都具有高度保守的酰胺酶特征家族序列，其分子量在 52-62 kDa 范围内。近平滑假丝酵母和米曲霉的酶形成同源四聚体，马红球菌 TB-60 的酶则以单体形式存在。大多数尿烷酶具有酰胺酶活性，而近平滑假丝酵母和米曲霉的酶对丙烯酰胺也表现出很高的活性，丙烯酰胺是一种 2A 类致癌物质。最近有报道称，脲酶和酯酶也表现出尿烷酶活性。尽管对 EC 的酶促降解的研究非常有限，但最近已经阐明了一些 EC 降解酶的序列，预计将开发和应用新的酶。关键点：
最近，一些尿烷酶序列已经阐明。
形成催化三联体的氨基酸残基是保守的。
尿烷酶具有酰胺酶活性，也可以降解丙烯酰胺。
