Open AccessElucidating the Electrochemical Mechanism of NG-Hydroxy-L-Arginine
Author(s) -
Mariah L. Arral,
Christian A Tooley,
Emily Ziino,
Jeffrey Mark Halpern
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ab643a
Subject(s) - cyclic voltammetry , chemistry , urea cycle , electrochemistry , urea , biosensor , oxide , electrode , analyte , voltammetry , arginine , analytical chemistry (journal) , inorganic chemistry , nuclear chemistry , chromatography , biochemistry , organic chemistry , amino acid
N G -Hydroxy-L-arginine (NOHA) is a stable intermediate product in the urea cycle that can be used to monitor the consumption of L-arginine by nitrous oxide synthase (NOS) to produce nitric oxide (NO) and L-citrulline. Research has implicated the urea cycle in many diseases and NO has cultivated interest as a potential biomarker for neural health. Electrochemical detection is an established, cost-effective method that can successfully detect low levels of analyte concentrations. As one of the few electrochemically active species in the urea cycle, NOHA shows promise as a biomarker for monitoring disruptions in this biochemical process. In this study, we show that NOHA has an oxidation peak at +355 mV vs Ag/AgCl at a glassy carbon electrode. In addition, cyclic voltammetry studies with structural analogs—alanine and N- hydroxyguanidine—allowed us to approximate the oxidation wave at +355 mV vs Ag/AgCl to be a one electron process. Diffusivity of NOHA was found using linear scan voltammetry with a rotating disk electrode and approximated at 5.50 × 10 −5 cm 2 s −1 . Ample work is still needed to make a robust biosensor, but the results here characterize the electrochemical activity and represent principle steps in making a NOHA biosensor.