Ornithine δ transaminase activity in Escherichia coli: Its identity with acetylornithine δ transaminase

Abstract

Procedures that have been developed for the purification of acetylornithine δ transaminase from E. coli W also lead to the simultaneous purification of ornithine δ transaminase. These 2 enzymatic activities have the same electrophoretic mobility and are identical immunochemically. Studies of inhibition kinetics demonstrate that the 2 substrates, acetylornithine and ornithine, compete for the same active site of acetylornithine δ transaminase; thus, the ornithine δ transaminase activity in E. coli is due to acetylornithine δ transaminase and not to a separate specific ornithine δ transaminase.