J. Technology and Education, Vol.23, No.2, pp.57-61 (2016)

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D”M‹ÛRubrobacter xylanophilus —R—ˆD-ƒAƒ~ƒmŽ_ƒIƒLƒVƒ_[ƒ[

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‚ŽR ŸŒÈ*1CâŒ³ ’m—¢1C‚‹´ ËŽi2Cˆ¢•” Ÿ³2, œA•” ˆ»”T1C‰z‹Ë •Ž™1

1•ŸˆäH‹Æ‚“™ê–åŠwZ•¨Ž¿HŠw‰Èi§916-8507•ŸˆäŒ§ŽI]Žs‰ºŽi’¬j

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*takayama@fukui-nct.ac.jp

 

Construction of a D-valine sensor using D-amino acid oxidase

of Rubrobacter xylanophilus

 

Katsumi TAKAYAMA*1, Chisato SAKAMOTO1, Shouji TAKAHASHI2,

Katsumasa ABE2, Ayano HIROBE1, and Takeji KOSHIGIRI1

 

1Department of Chemistry & Biology Engineering, Fukui National College of Technology

(Geshi, Sabae 916-8507, Japan)

2Department of Bioengineering, Nagaoka University of Technology

(Kamitomioka, Nagaoka 940-2188, Japan)

 

(Received September 20, 2016; Accepted October 20, 2016)

 

Abstract

A biosensor for D-valine was constructed by using D-amino acid oxidase of Rubrobacter xylanophilus (RxDAO) as a biocatalyst. This enzymatic reaction consists of enzymatic and nonenzymatic reactions. During the enzymatic reaction process, an imino acid is produced that is accompanied by oxygen consumption and hydrogen peroxide formation. In this study, RxDAO was trapped on horseradish peroxidase and an osmium polymer-modified carbon paste electrode (RxDAO-HRP-Os CPE). The detection limit of RxDAO-HRP-Os CPE was about 5 ƒÊM for D-valine. The response of RxDAO-HRP-Os CPE to amino acids corresponded with the substrate selectivity of RxDAO without D-tyrosine. The micromolar concentration level of D-valine can be detected with the coexistence of 1 mM L-valine. The linear relationship of the calibration curve was between 80 ƒÊM and 1 mM. The response was maintained over 2 weeks. RxDAO was not deactivated at 50Ž.

 

Keywords:  D-valine, Rubrobacter xylanophilus, D-amino acid oxidase, biosensor, HRP osmium polymer

 

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