A colorimetric assay method for measuring D-glutamate cyclase activity

Masumi Katane, Risa Motoda, Makoto Ariyoshi, Shuhei Tateishi, Kazuki Nakayama, Yasuaki Saitoh, Tetsuya Miyamoto, Masae Sekine, Masashi Mita, Kenji Hamase, Satoaki Matoba, Kumiko Sakai-Kato, Hiroshi Homma

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


In mammals, metabolism of free D-glutamate is regulated by D-glutamate cyclase (DGLUCY), which reversibly converts D-glutamate to 5-oxo-D-proline and H2O. Metabolism of these D-amino acids by DGLUCY is thought to regulate cardiac function. In this study, we established a simple, accurate, and sensitive colorimetric assay method for measuring DGLUCY activity. To this end, we optimized experimental procedures for derivatizing 5-oxo-D-proline with 2-nitrophenylhydrazine hydrochloride. 5-Oxo-D-proline was derivatized with 2-nitrophenylhydrazine hydrochloride in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide as a catalyst to generate the acid hydrazides, whose levels were then determined using a colorimetric method. Under optimized conditions, we examined the sensitivity and accuracy of the colorimetric method and compared our technique with other methods by high-performance liquid chromatography with ultraviolet–visible or fluorescence detection. Moreover, we assessed the suitability of this colorimetric method for measuring DGLUCY activity in biological samples. Our colorimetric method could determine DGLUCY activity with adequate validity and reliability. This method will help to elucidate the relationship among DGLUCY activity, the physiological and pathological roles of D-glutamate and 5-oxo-D-proline, and cardiac function.

Original languageEnglish
Article number113838
JournalAnalytical Biochemistry
Publication statusPublished - Sept 15 2020

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology


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