Superoxide dismutase and catalase are required to detect •NO from both coupled and uncoupled neuronal no synthase

Reif, A., Shutenko, Z. V., Feelisch, M. and Schmidt, H. H. H. W. (2004) Superoxide dismutase and catalase are required to detect •NO from both coupled and uncoupled neuronal no synthase. Advances in Free Radical Biology & Medicine, 37, (7), 988-997. (doi:10.1016/j.freeradbiomed.2004.07.005). (PMID:15336315).


Full text not available from this repository.


Despite numerous approaches to measuring nitric oxide (NO) formation from purified NO synthase (NOS), it is still not clear whether (.-)NO is a direct or indirect product of the NO synthase reaction. The direct detection of catalytically formed (.-)NO is complicated by side reactions with reactive oxide species like H(2)O(2) and superoxide. The aim of the present study was therefore to reinvestigate these reactions both electrochemically and by chemiluminescence detection with particular emphasis on the requirement for cofactors and their interference with (.-)NO detection. Flavins were found to generate large amounts of H(2)O(2) and were therefore excluded from subsequent incubations. Under conditions of both coupled and uncoupled catalysis, SOD was absolutely required to detect (.-)NO from NOS. H(2)O(2) formation took place also in the presence of SOD and gave a smaller yet significant interfering signal. Similar data were obtained when the proposed intermediate N(omega)-hydroxy-l-arginine was utilized as substrate. In conclusion, standard Clark-type ()NO electrodes are cross-sensitive to H(2)O(2) and therefore both SOD and catalase are absolutely required to specifically detect (.-)NO from NOS.

Item Type: Article
Digital Object Identifier (DOI): doi:10.1016/j.freeradbiomed.2004.07.005
ISSNs: 8755-9668 (print)
Related URLs:
Keywords: nitric oxide, NOS, superoxide, catalase, SOD, flavins, NO electrode, free radicals
Subjects: Q Science > QD Chemistry
Q Science > QH Natural history > QH301 Biology
R Medicine > R Medicine (General)
Divisions : Faculty of Medicine > Clinical and Experimental Sciences
ePrint ID: 337843
Accepted Date and Publication Date:
1 October 2004Published
22 July 2004Made publicly available
Date Deposited: 07 Jun 2012 15:28
Last Modified: 31 Mar 2016 14:27

Actions (login required)

View Item View Item