Enhancement of luminol chemiluminescence by cysteine and glutathione.
Cysteine enhancement of cobalt(II)-catalysed chemiluminescence of hydrogen peroxide and luminol occurs in carbonate buffer (but not in borate buffer), whether cysteine mixes with hydrogen peroxide before it mixes with luminol-cobalt(II) or vice versa. Enhancement was measured by the ratio of the signals in the presence and absence of cysteine; standard errors were generally < 5% of the mean ratio. Cystine in sufficiently acidic solution also enhances the chemiluminescence but otherwise diminishes the emission. The emission is also inhibited by glutathione. A mixed solution of cysteine and cystine gives rise to enhanced signals. In all the above cases, enhancement occurs only in the presence of a cobalt(II) catalyst. Luminol-peroxynitrite chemiluminescence is enhanced by cysteine and by glutathione without the presence of a catalyst.
Wheatley
R A
RA
Department of Chemistry, University of Hull, Hull, UK HU6 7RX. rawheatley@canadalane.demon.co.uk
Sariahmetoğlu
M
M
Cakici
I
I
D003035:Cobalt / Q000032:analysis*; D003545:Cysteine; D005978:Glutathione; D006861:Hydrogen Peroxide / Q000032:analysis*; D008163:Luminescent Measurements; D008165:Luminol; D017382:Reactive Oxygen Species
D017382:Reactive Oxygen Species; D003035:Cobalt; D008165:Luminol; D006861:Hydrogen Peroxide; D005978:Glutathione; D003545:Cysteine