DETECTION OF DITYROSINE IN APOFERRITIN

Laser-excited fluorescence spectroscopy was adopted for dityrosine det ection in horse spleen apoferritin. Dityrosine was identified in horse spleen apoferritin. Fractionation of acid-hydrolyzed horse spleen apo ferritin showed fluorescence attributed to dityrosine, and other compo unds, excited by 325-nm laser radiation. The other fluorescent compoun ds resulted in a broad fluorescence emission spectrum of horse spleen apoferritin. The broad emission band overlapped with the fluorescence emission spectrum of pure dityrosine. Fractionation of horse spleen ap oferritin acid hydrolysate prior to laser-excited fluorescence detecti on was necessary for dityrosine quantitative analysis. The concentrati on of dityrosine in horse spleen apoferritin was 2.5% (mol/mol), estim ated from the method of standard addition.