Biotechnology Research Center, Department of Biotechnology, Toyama Prefectural University, Imizu, Japan.
Anal Biochem. 2010 Nov 1;406(1):19-23. doi: 10.1016/j.ab.2010.06.045. Epub 2010 Jul 1.
This article describes a successful application of l-lysine epsilon-oxidase (EC 1.4.3.20) for l-lysine determination. l-Lysine epsilon-oxidase was isolated from culture supernatant of Marinomonas mediterranea NBRC 103028(T) and was used for l-lysine determination. Comparison of the characteristics of l-lysine epsilon-oxidase with l-lysine alpha-oxidase, a commercial enzyme used for l-lysine determination, suggests that the use of l-lysine epsilon-oxidase would be more valuable for the determination of l-lysine because of its selectivity and sensitivity, especially in samples with low l-lysine concentration. The enzyme acted only on l-lysine and l-ornithine, to which the relative activity was only 3.4% of that on l-lysine. The value obtained by the colorimetric assay using l-lysine epsilon-oxidase and horseradish peroxidase was not affected by l-ornithine. The enzyme also shows a higher affinity for l-lysine (K(m)=0.0018mM). l-Lysine determination using l-lysine epsilon-oxidase in human plasma and serum was examined. The measured values were close to values determined by instrumental analyses using the precolumn AccQ.Tag Ultra Derivatization Kit. These results suggest that l-lysine epsilon-oxidase can be used for diagnosis based on plasma l-lysine concentration. This is the first report on the application of l-lysine epsilon-oxidase.
本文描述了 l-赖氨酸 ε-氧化酶（EC 1.4.3.20）在 l-赖氨酸测定中的成功应用。l-赖氨酸 ε-氧化酶从 Marinomonas mediterranea NBRC 103028(T)的培养上清液中分离出来，并用于 l-赖氨酸的测定。与用于 l-赖氨酸测定的商业酶 l-赖氨酸 α-氧化酶的特性比较表明，由于其选择性和灵敏度，特别是在低 l-赖氨酸浓度的样品中，使用 l-赖氨酸 ε-氧化酶进行 l-赖氨酸测定将更有价值。该酶仅作用于 l-赖氨酸和 l-鸟氨酸，对其相对活性仅为 l-赖氨酸的 3.4%。使用 l-赖氨酸 ε-氧化酶和辣根过氧化物酶进行比色测定所获得的值不受 l-鸟氨酸的影响。该酶对 l-赖氨酸的亲和力也更高（K(m)=0.0018mM）。对人血浆和血清中的 l-赖氨酸进行了使用 l-赖氨酸 ε-氧化酶的测定。测定值与使用 AccQ.Tag Ultra 衍生试剂盒的仪器分析所确定的值接近。这些结果表明，l-赖氨酸 ε-氧化酶可用于基于血浆 l-赖氨酸浓度的诊断。这是关于 l-赖氨酸 ε-氧化酶应用的首次报道。
