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ID 52123
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Characterization of L-Arginine Oxidase Made from L-Glutamate Oxidase
Author
Nakai, Ryuichiro
Fujino, Shihoko
Utsumi, Tomohiro
Kusakabea, Hitoshi
Abstract
 L‒Glutamate oxidase (LGOX) from Streptomyces sp. X‒119‒6 has strict substrate specificity toward L‒glutamate. Recently, we solved the X‒ray crystal structure of LGOX and this revealed that Arg305 in the active site is the key residue involved in substrate recognition. Therefore, we created 19 mutant enzymes of R305X‒LGOX by saturation mutagenesis. One of them R305D‒LGOX, Arg305 substituted with Asp exhibited oxidase activity for L‒Arg. Optimum pH of R305D‒LGOX mutant enzyme was pH 8.5. Interestingly, the activity of R305D‒LGOX toward L‒Arg was inhibited by phosphate. And furthermore, the substrate specificity of R305D‒LGOX was affected by using buffer. The results of inhibition analysis suggest, that phosphate is a competitive inhibitor of R305D‒LGOX when L‒Arg is used as substrate. Kinetic analysis of R305D‒LGOX showed that Km value and kcat value of R305D‒LGOX toward l-Arg were 0.68 mM and 6.7 s-1 respectively. In this study, we showed that R305D‒LGOX mutant enzyme is a novel l-arginine oxidase and useful for l-arginine biosensor.
Keywords
L-glutamate oxidase
L-arginine oxidase
biosensor
modified substrate specificity
L-amino acid oxidase
Note
原著論文 (Original paper)
Published Date
2014-02-01
Publication Title
岡山大学農学部学術報告
Publication Title Alternative
Scientific Reports of the Faculty of Agriculture Okayama University
Volume
volume103
Publisher
岡山大学農学部
Publisher Alternative
Faculty of Agriculture, Okayama University
Start Page
5
End Page
9
ISSN
2186-7755
Content Type
Departmental Bulletin Paper
language
日本語
File Version
publisher
Refereed
False
Eprints Journal Name
srfa