The stereochemistry of the enzymic decarboxylation of L -arginine and of L -ornithine

The decarboxylation of L-ornithine to yield putrescine, catalyzed by the L-ornithine decarboxylase (EC 4.1.1.17) of E. coli, and the decarboxylation of L-arginine to yield agmatine, catalyzed by the L-arginine decarboxylase (EC 4.1.1.19) of E. coli, take place with retention of configuration.