Synthesis of Nω‐Phospho‐l‐arginine by Biocatalytic Phosphorylation of l‐Arginine

The Nw-phospho-l-arginine energy-buffering system is mainly present in invertebrates for regulating energy requirements when it is highly needed, such as in the flight muscles of an insect or when energy supply fluctuates, as in the medically important protozoa Trypanosoma brucei, Trypanosoma cruzi, and Leishmania major. The lack of availability of this important metabolite was due to a tedious chemical procedure, by which Nw-phospho-l-arginine was prepared in over 5 reaction steps in a low yield. Therefore, we aimed at improving the synthetic methodology for the preparation of this important metabolite. As site- and enantioselective kinases have been very useful catalysts for biocatalytic phosphorylations in straightforward syntheses of phosphorylated metabolites, a stable and selective arginine kinase has been selected for the selective phosphorylation of l-arginine. The Arg gene has been cloned and expressed in E. coli and a highly active arginine kinase has been prepared. A simple synthesis of Nw-phospho-l-arginine has been developed by arginine kinase catalyzed phosphorylation of l-arginine combined with the recycling of the phosphorylating agent ATP by using the phosphoenolpyruvate/pyruvate kinase system. After standard work-up, the desired product Nwphospho-l-arginine was obtained in gram quantities and in one step.