Abstract
1. Phosphopantothenoylcysteine decarboxylase [EG 4.1.1.36] was highly purified from rat liver and some properties of the decarboxylase are reported. 2. Using a crude preparation and the purified enzyme, it was confirmed that the enzymatic decarboxylation of the cysteine moiety in the course of CoA biosynthesis in rat liver occurred with phosphopantothenoylcysteine but not with pantothenoylcysteine as the substrate.