Effect of various alanine analogues on the l-alanine-adding enzyme from Escherichia coli

An extract from Escherichia coli containing the l-alanine-adding enzyme with a high specific activity was prepared. Several compounds structurally related to l-alanine were tested as inhibitors of this activity. Intact amino and carboxyl groups were necessary for an interaction with the enzyme. Certain halogenated (haloalanines) or unsaturated (l-vinylglycine, l-propargylglycine, 3-cyano-l-alanine) amino acids were good inhibitors. Radioactive glycine, serine and 1-aminoethylphosphonic acid were tested as substrates. Whereas glycine or l-serine gave rise to the formation of the corresponding nucleotide product, no synthesis of UDP-N-acetylmuramyl-l-1-aminoethylphosphonic acid could be detected.