Barry R J, Bowman E, McQueney M, Dunaway-Mariano D
Department of Chemistry and Biochemistry, University of Maryland, College Park 20742.
Biochem Biophys Res Commun. 1988 May 31;153(1):177-82. doi: 10.1016/s0006-291x(88)81205-1.
The biosynthetic reaction pathway leading to the natural product, 2-aminoethylphosphonate in Tetrahymena pyriformis has been elucidated. Incubation of [32P]PEP and [14C]PEP with T.pyriformis cellular homogenate fortified with Mg2+ and alanine/pyridoxal phosphate, yielded 2-aminoethylphosphonate as the minor reaction product (2-5% yield) and phosphoglycerate and pyruvate plus orthophosphate as the major products. Inclusion of thiamine pyrophosphate in the reaction mixture increased the yield of 2-aminoethylphosphonate by a factor of 10. Incubation of phosphonoacetaldehyde or phosphonopyruvate in the cellular homogenate also provided 2-aminoethylphosphonate. The cellular homogenate catalyzed the transformation of phosphonoacetaldehyde to 2-aminoethylphosphonate in an ca. 80% yield. However, the maximum yield of 2-aminoethylphosphonic acid obtained by use of phosphonopyruvate was only 15%. The major reaction pathways induced by treatment of phosphonopyruvate with the cellular extract involved its competitive conversion to PEP and pyruvate plus orthophosphate.
