2-Aminoethylarsonic acid as an analogue of ethanolamine phosphate. Endowment of ethanolamine-phosphate cytidylyltransferase with CTP pyrophosphatase activity.

2-Aminoethylarsonic acid was tested for its ability to act as a substrate for ethanolamine-phosphate cytidylytransferase as a cytidylyl acceptor in place of ethanolamine phosphate. The expected product, like all mixed anhydrides of arsonic acids, should hydrolyse spontaneously with regeneration of the substrate analogue and CMP formation; such CMP production was observed. The limiting velocity with aminoethylarsonic acid is about 90% that with ethanolamine phosphate, and the Michaelis constant is below 20 mM.