Dipeptidase activity was detected in the soluble fraction of radish (Raphanus sativus L.) cotyledon, and the purified enzyme had a specific activity of 7.3 nkat/mg protein for hydrolyzing L-cysteinylglycine. The dipeptidase was found to be a hexameric metalloenzyme, composed of homological 55 kDa-subunits. This is the first glutathione catabolism-related dipeptidase isolated from higher plants.
