Structural characterization of L-amino acid oxidase with high substrate specificity and industrial applications

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560962
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biofunction/Bioprocess
• Research Institution: Okayama University
• Principal Investigator: INAGAKI KENJI 岡山大学, その他の研究科, 教授 (80184711)
• Co-Investigator(Kenkyū-buntansha): IMADA Katsumi 大阪大学, 大学院理学研究科, 教授 (40346143)
• Co-Investigator(Renkei-kenkyūsha): TAMURA Takashi 岡山大学, 大学院環境生命科学研究科, 教授 (40253009) ; INAGAKI Junko 岡山大学, 大学院医歯(薬)学総合研究科, 助教 (90271056)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: L-アミノ酸オキシダーゼ / L-グルタミン酸オキシダーゼ / L-リシンオキシダーゼ / 基質認識機構 / X線結晶構造解析 / 異種発現系構築 / 基質特異性の改変 / 抗腫瘍性酵素

Outline of Final Research Achievements

We determined the crystal structure of two L-amino acid oxidases with high substrate specificity, L-glutamate oxidase (LGOX) from Streptomyces sp. X-119-6 and L-lysine α-oxidase (LysOX) from Trichoderma viride. and we analyzed the molecular mechanism of the substrate recognition of L-amino acid oxidases with high substrate specificity. X-ray crystal structure of LGOX revealed that Arg305 in the active site is the key residue involved in substrate recognition. We created 19 mutant enzymes by substitution of Arg305. Some of them, R305D-LGOX, R305L-LGOX, and R305H-LGOX lost oxidase activity for L-Glu, and exhibited a new oxidase activity for L-Arg, L-His, and L-Tyr, respectively. These progress and findings will provide a great contribution to further industrial application of these enzymes.

Free Research Field

生物機能工学