Synthesis of the proline analogue [2,3-3H]azetidine-2-carboxylic acid. Uptake and incorporation in Arabidopsis thaliana and Escherichia coli.

Azetidine-2-carboxylic acid, the 4-membered ring noranalogue of proline, is regularly used in the study of proline metabolism as well as the study of protein conformation. We prepared D,L-[2,3-3H]azetidine-2-carboxylic acid with an optimized 10% yield from commercially available 4-amino-[2,3-3H]butyric acid. Purification was performed by fast-protein liquid chromatography. The biological activity was checked in both Arabidopsis thaliana and Escherichia coli. The obtained specific activity of 10 mCi/mmol was sufficient for most uptake and incorporation studies.