title: Determination of plasma and serum L-lysine using L-lysine epsilon-oxidase from Marinomonas mediterranea NBRC 103028(T).
abstract: 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.
authors.affiliation: Biotechnology Research Center, Department of Biotechnology, Toyama Prefectural University, Imizu, Japan.
authors.forename: Motoki
authors.initials: M
authors.lastname: Matsuda
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Asano
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D055162:Biocatalysis; D001774:Blood Chemical Analysis / Q000379:methods*; D006801:Humans; D008239:Lysine / Q000097:blood* / Q000378:metabolism*; D053544:Marinomonas / Q000201:enzymology*; D010084:Oxidation-Reduction; D013379:Substrate Specificity
chemical_list: D000594:Amino Acid Oxidoreductases; D008239:Lysine