title: Enhancement of luminol chemiluminescence by cysteine and glutathione.
abstract: 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.
authors.affiliation: Department of Chemistry, University of Hull, Hull, UK HU6 7RX. rawheatley@canadalane.demon.co.uk
authors.forename: R A
authors.initials: RA
authors.lastname: Wheatley
authors.forename: M
authors.initials: M
authors.lastname: Sariahmetoğlu
authors.forename: I
authors.initials: I
authors.lastname: Cakici
mesh_terms: D003035:Cobalt / Q000032:analysis*; D003545:Cysteine; D005978:Glutathione; D006861:Hydrogen Peroxide / Q000032:analysis*; D008163:Luminescent Measurements; D008165:Luminol; D017382:Reactive Oxygen Species
chemical_list: D017382:Reactive Oxygen Species; D003035:Cobalt; D008165:Luminol; D006861:Hydrogen Peroxide; D005978:Glutathione; D003545:Cysteine