A sensitive radiometric assay for cysteic acid decarboxylase activity in crude enzyme preparations of rat liver and brain

Comp Biochem Physiol B. 1977;58(1):115-7. doi: 10.1016/0305-0491(77)90136-5.


1. A method is described for the synthesis of L-[U-14C]cysteic acid from L-[U-14C] cysteine hydrochloride and for its subsequent utilisation as a substrate for cysteic acid decarboxylase activity in liver and brain. 2. The enzyme determination relies on the entrapment of radio-labelled carbon dioxide in Hyamine hydroxide. 3. The assay is sensitive, reliable and convenient and is particularly suitable for measuring the activity of the decarboxylase in crude enzyme preparations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / enzymology*
  • Carboxy-Lyases / metabolism*
  • Cysteic Acid / metabolism
  • Hydrogen-Ion Concentration
  • Liver / enzymology*
  • Male
  • Radiometry
  • Rats
  • Rats, Inbred Strains
  • Substrate Specificity


  • Cysteic Acid
  • Carboxy-Lyases
  • cysteic acid decarboxylase