Abstract
In this study, we reported that a bioluminescent assay for nitric oxide (NO) was developed utilizing the biological enzyme activity of soluble guanylate cyclase (sGC) and a bioluminescent assay for pyrophosphate involving the pyruvate phosphate dikinase (PPDK)-luciferin/Luciferase reaction. Pyrophosphate (PPi), which is released concomitantly when NO binds to soluble guanylate cyclase, was measured employing the PPDK/Luciferase reaction. NO binds to soluble guanylate cyclase specifically; thus, this assay is undisturbed by nitrate anhydride, or
. Consequently, the measurable range of NO obtained in the proposed method is 200–20,000 nM; the detection limit was 200 fmol/assay. NO released from nitrate medicine was measured utilizing this assay. As a result, NO released from isosorbide nitrate was detected. In conclusion, we suggest in this report that the technique for NO might be suitable as a quality check method for the pharmacodynamic action of nitrate medicines and in development of new medicines.
Acknowledgments
This work was partially supported by Showa University Research Fund and “High-Tech Research Center” Project for Private Universities: matching fund subsidy from MEXT (Ministry of Education, Culture, Sports, Science and Technology), 2007–2009.